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Every business registered under GST has to report its sales, purchases, and tax liability to the government on a set schedule, whether or not there was a single transaction that month. That's what GST return filing means in practice: logging into the GST portal, pulling together your outward and inward supply data, reconciling input tax credit, and submitting the right form before the due date. Miss it, and the portal charges a late fee automatically, no notice required.
This page walks through every return type you're likely to deal with, the current due dates, what's changed on the GST portal through 2026, and how to file without losing input tax credit to a reconciliation mismatch you didn't catch in time.
A GST return is a statement a registered taxpayer submits on the government's GST portal, showing outward supplies (what you sold), inward supplies and the input tax credit you're claiming on them, and the net tax payable after adjusting that credit. Filing isn't optional once you hold a GSTIN, and it doesn't pause just because a month had no sales. A period with zero transactions still needs a return, called a nil return, and skipping it draws the same late fee mechanism as skipping a return with real numbers on it.
Most businesses end up dealing with two returns every filing cycle: GSTR-1, which reports your sales, and GSTR-3B, the summary return where you declare your net liability and pay tax. Larger or more specialised businesses layer on annual returns, TDS/TCS returns, or ISD returns depending on what they do.
Filing schedules and return forms depend entirely on your registration type, scheme selection, and transactions. Below is the list of active GST returns:
These two forms get filed together every cycle, but they're not interchangeable.
If you're on the QRMP scheme (turnover up to Rs. 5 crore, opting for quarterly filing), you still file GSTR-1 and GSTR-3B quarterly, but you pay tax monthly through a simplified challan, using either the fixed-sum method based on your last quarter's liability or a self-assessed amount.
Both statements list the purchases your suppliers have reported against your GSTIN, but they behave differently. GSTR-2A updates in real time as suppliers file, which makes it useful for tracking but unreliable as a claim basis since it keeps changing. GSTR-2B is a static snapshot generated once a month, and it's the one that actually determines what input tax credit you're eligible to claim in that period's GSTR-3B.
Since October 2025, this connection has tightened considerably through the Invoice Management System (IMS). Every inward invoice now needs an explicit action on the IMS dashboard: accept, reject, or leave pending. Only accepted (or automatically deemed-accepted) invoices flow into GSTR-2B and become claimable credit. Rejected invoices are excluded outright. From April 1, 2026, using IMS became mandatory for every regular taxpayer filing GSTR-3B, and the portal now applies what's commonly called a Zero Mismatch check: GSTR-3B is blocked from filing if the ITC you've claimed exceeds what's actually sitting in your GSTR-2B. There's no override button anymore. If a supplier hasn't filed on time, or you haven't cleared a pending invoice in IMS, your own return can get stuck until it's resolved, which makes checking GSTR-2B before the 11th of each month worth building into your routine rather than treating it as optional.
The recurring pattern for regular filers looks like this:
Note: CBIC issues one-off extensions from time to time, GSTR-3B for March 2026 got a short extension, for instance. Always cross-check the exact date against the GST portal's own calendar before you file, since a table in an article is never a substitute for the notification itself.
Two things worth knowing beyond the numbers. First, late fees have to be paid in cash from your electronic cash ledger, input tax credit can't be used to settle them. Second, since mid-2025 the portal enforces a three-year time bar: GSTR-1, GSTR-3B, GSTR-4, GSTR-5 through 8, and GSTR-9 can no longer be filed at all once more than three years have passed from the original due date. If you have very old pending returns, this isn't a "get to it eventually" situation anymore, those filings become permanently blocked once the window closes.
For quarterly GSTR-1 filers who want to share invoice-level data with buyers mid-quarter without waiting for the full quarterly filing, the Invoice Furnishing Facility (IFF) lets you upload B2B invoices monthly even though your actual GSTR-1 filing stays quarterly.
If you've paid more GST than you owe, whether from zero-rated exports, an inverted duty structure where your input tax rate is higher than your output rate, or simply an error in the cash ledger, you can claim it back through Form RFD-01 on the GST portal.
The process runs on fairly fixed timelines: an acknowledgement (RFD-02) within 15 days of a complete application, a provisional refund of up to 90% within 7 days for eligible zero-rated and (as of Budget 2026) inverted-duty claims, and a final sanction order (RFD-06) within 60 days of acknowledgement. If the department takes longer than 60 days, you're entitled to 6% annual interest on the delay. Refund claims have to be filed within two years of the relevant date (generally the export or payment date), and that deadline doesn't bend for a late filing, once it passes, the claim is gone for good.
Moving goods worth more than Rs. 50,000 in a single consignment typically requires an e-way bill, generated on the separate e-way bill portal using your GSTIN. If a transporter, rather than you or the buyer, is moving the goods, the e-way bill needs a valid Transporter ID entered against it so the vehicle can be tracked and the bill updated with vehicle details en route. Transporters register once on the e-way bill portal to get this ID, and it gets reused across every shipment they carry, so it's worth setting up before your first dispatch rather than scrambling at the loading dock.
If your aggregate turnover crossed Rs. 5 crore in any year since 2017-18, e-invoicing isn't optional for your B2B and export invoices. Every such invoice has to be reported to the Invoice Registration Portal (IRP) to receive an Invoice Reference Number (IRN) and QR code before it counts as valid under GST law. Once you cross that threshold in any year, the obligation stays even if your turnover later drops, so don't assume a lean year removes it.
This connects directly to return filing: e-invoice data auto-populates into your GSTR-1, cutting down manual entry considerably. It does not replace GSTR-1 filing itself. If your turnover is Rs. 10 crore or above, there's an additional constraint to track: invoices, credit notes, and debit notes have to reach the IRP within 30 days of the document date, or the portal rejects them outright, and a rejected invoice is invalid for GST purposes on both sides, meaning your buyer loses that input tax credit too. SEZ units, banks, insurers, goods transport agencies, and passenger transport services are exempt from the e-invoicing mandate regardless of turnover.
GSTR-3A isn't a return you file, it's a notice the system sends when you've missed filing GSTR-3B, GSTR-4, GSTR-5, GSTR-6, GSTR-7, GSTR-8, or GSTR-10 by the due date. Once you get one, you have 15 days to file the pending return along with whatever late fee and interest apply. Ignore it past that window, and the officer can move to a best-judgment assessment under Section 62, estimating your tax liability without your input, which is a considerably worse position to negotiate from than just filing the return yourself. You can check for any pending GSTR-3A notices under Services > User Services > View Notices and Orders on the GST portal.
If a return period had no sales, no purchases, and nothing to report, you still file a nil return rather than skip it. On the portal, this takes the same route as a regular filing, just with zero values entered, and it's confirmed through DSC or EVC like any other submission. GSTR-3B also supports nil filing through SMS from your registered mobile number for businesses that want a faster route when there's genuinely nothing to report, though most filers now find it just as quick to log in and submit through the dashboard given how tightly IMS and GSTR-2B checks are now woven into the regular filing flow.
If you're registered under the composition scheme, your filing cycle looks different from a regular taxpayer's. You file CMP-08 quarterly, a simple statement declaring turnover and tax paid at your flat composition rate, and GSTR-4 annually, which consolidates the full year. There's no GSTR-1 or GSTR-3B to worry about, and no input tax credit to reconcile, since composition dealers don't claim ITC in the first place.
LegalDev's GST return filing service starts at Rs. 599 per return, covering GSTR-1 and GSTR-3B preparation, IMS reconciliation, and filing on your behalf, with typical turnaround inside 12 hours of you sharing your sales and purchase data. Annual returns (GSTR-9/9C) and refund applications are quoted separately given the additional reconciliation work involved. Pricing is confirmed upfront before we start, no charges added once the filing is done.
Filing correctly now takes more than portal access. Between IMS actions that need to happen before every GSTR-3B, outward figures that are locked and can only be corrected through GSTR-1A, and a hard ITC check against GSTR-2B, a single missed step can block your return at the worst possible moment. LegalDev's team tracks your IMS dashboard, reconciles GSTR-2B against your purchase register before the filing window opens, and manages the full cycle, monthly or quarterly GSTR-1 and GSTR-3B, annual returns, and refund applications, so a supplier's late filing doesn't become your compliance problem.
Not always, but it depends on what your GST profile actually looks like. If you're a single-GSTIN business with straightforward B2B or B2C sales, no exports, no e-commerce marketplace income, and a handful of invoices a month, you can file GSTR-1 and GSTR-3B yourself once you understand the portal and the Invoice Management System (IMS) workflow that now sits ahead of every GSTR-3B filing.
Where a CA earns their fee is reconciliation. Since GSTR-3B's outward figures are now locked and pulled directly from your filed GSTR-1, and ITC is hard-checked against GSTR-2B with no override, a single missed IMS action or an unnoticed supplier mismatch can block your return from filing at all. A CA who reconciles your purchase register against GSTR-2B before the filing window opens catches that before it becomes a blocked filing on the 20th.
The honest middle ground: file yourself if your transaction volume is low and your accounting is clean. Bring in professional help once you cross into multiple invoice types, interstate supply, ITC claims that need scrutiny, or a turnover level where a filing error gets expensive fast.
LegalDev's GST return filing service builds exactly this GSTR-2B reconciliation into every monthly cycle, so you don't have to make that call alone.
For a small business or freelancer with limited invoices, monthly GSTR-1 and GSTR-3B filing through a CA or accounting firm typically runs somewhere between Rs. 500 and Rs. 2,000 a month. Businesses with moderate transaction volume and ITC reconciliation needs usually land between Rs. 2,000 and Rs. 5,000 a month, and larger businesses with hundreds of invoices, multiple GST rates, or e-way bill activity can pay Rs. 5,000 to Rs. 15,000 or more.
Quarterly QRMP filers generally pay less per cycle than monthly filers, since there are fewer filing events even though the underlying tax payments stay monthly. Annual returns are priced separately: GSTR-9 preparation commonly costs a few thousand rupees, and GSTR-9C, which applies above Rs. 5 crore turnover, costs more given the reconciliation against audited financials.
Two things move the price more than anything else: how many invoices you generate each month, and whether your ITC claims need active reconciliation against GSTR-2B rather than a quick glance. A nil-return business pays close to nothing; a business juggling e-commerce TCS, exports, and multiple GSTINs pays at the top of the range.
LegalDev prices its GST filing plans on this same scope basis, so you know upfront whether reconciliation is included rather than billed separately later.
Yes, nothing in GST law requires you to use a CA or consultant. The GST portal is built for taxpayers to self-file, and plenty of small businesses and freelancers do exactly that every month.
What's changed is the margin for error. Before the IMS and GSTR-2B tightening that rolled out through 2025 and 2026, you could adjust a mismatch directly inside GSTR-3B. Now, outward figures come locked from your filed GSTR-1, and any ITC claim above what's sitting in your GSTR-2B blocks the filing outright. Self-filing still works, but it now means actively working through your IMS dashboard, accepting or rejecting inward invoices, and checking your GSTR-2B before the 11th of each month rather than treating GST as a once-a-month five-minute task.
If your business has one GSTIN, a manageable number of invoices, and you're comfortable spending an hour or two on the portal each cycle, self-filing is entirely realistic. Where it stops being realistic is once ITC reconciliation, exports, or multiple state registrations enter the picture.
If you'd rather hand off the IMS habit altogether, LegalDev's GST filing service takes over that reconciliation every single cycle.
Start with the two returns you'll deal with almost every cycle: GSTR-1, where you report every sale invoice, and GSTR-3B, the summary return where you declare tax liability and pay. Both go on the same schedule, monthly by default, or quarterly if you've opted into the QRMP scheme for turnover up to Rs. 5 crore.
The single habit that matters most as a new filer is checking your Invoice Management System (IMS) dashboard before you touch GSTR-3B. Every inward invoice your suppliers report needs an action, accept, reject, or leave pending, and only accepted invoices become claimable credit in your GSTR-2B. Skip this step and your ITC claim can exceed what's actually available, which blocks the filing.
A period with zero transactions still needs a return. This is a nil return, filed with zero values, and skipping it draws the same late fee as skipping a real one, just at a lower capped rate. Alongside this, keep your sales invoices, purchase invoices, and bank statements organised from day one; reconstructing three months of GST data under deadline pressure is where most beginner mistakes happen.
LegalDev's GST filing service is built around this same GSTR-1-then-GSTR-3B sequence, which is usually the easiest way for a new filer to get the habit right from month one.
Most regular taxpayers file GSTR-1 and GSTR-3B monthly. If your aggregate turnover is up to Rs. 5 crore, you can opt into the QRMP scheme instead, which moves GSTR-1 and GSTR-3B to a quarterly filing cycle while you still pay tax every month through a simplified challan.
On top of the sales-and-summary cycle, there's an annual layer. GSTR-9, the annual return, is mandatory once your turnover crosses Rs. 2 crore in a financial year and optional below that. GSTR-9C, a reconciliation statement against your audited accounts, kicks in above Rs. 5 crore turnover. Composition scheme dealers follow a different rhythm entirely: CMP-08 quarterly and GSTR-4 annually, with no GSTR-1 or GSTR-3B at all.
So the honest answer depends on your registration type and turnover, not a single fixed number. A small QRMP-eligible service provider might file four times a year for GSTR-1/3B plus one annual return; a larger monthly filer with e-way bill activity might touch the portal 25 or more times a year once TDS, TCS, or ISD obligations are added in.
LegalDev tracks all of these cycles, monthly, QRMP, and annual, on a client's behalf so the right return goes in on the right schedule without anyone having to remember four different calendars.
Registration and filing are two different stages of the same compliance relationship, and mixing them up is a common source of confusion for new business owners.
GST registration is the one-time step where you apply for a GSTIN, the 15-digit number that identifies your business under GST law. You need it once your turnover crosses the applicable threshold, or immediately if you fall into a category that requires registration regardless of turnover, such as e-commerce sellers or businesses making interstate supplies. Registration typically takes three to seven working days with Aadhaar authentication, longer if you opt out of it.
GST filing is what happens after you have that GSTIN: the recurring, periodic submission of returns reporting your sales, purchases, and tax liability. You register once; you file every month or quarter for as long as the registration stays active. Skipping registration when you're liable is a compliance failure at the threshold; skipping filing after you're registered is a compliance failure on the calendar, and the two attract different consequences.
LegalDev handles both ends of this relationship, GST registration and the periodic filings that follow, so the two stages stay connected rather than becoming separate projects.
It depends almost entirely on turnover and what you're selling. For services, including most side hustles like freelancing, consulting, or content work, registration becomes mandatory once your aggregate turnover crosses Rs. 20 lakh in a financial year (Rs. 10 lakh in special category states such as the northeastern states and a few hill states). For goods, the threshold is higher, Rs. 40 lakh in normal category states.
Aggregate turnover is calculated on a PAN-wide basis, not per business. If you already have a full-time salary and your side business turnover alone stays under the threshold, you're generally not required to register, though you can register voluntarily to claim input tax credit and add credibility with B2B clients.
Two situations override the threshold entirely: selling through an e-commerce platform, and making interstate supplies of certain kinds. If your side business sells through Amazon, Flipkart, Meesho, or a similar marketplace, GST registration becomes mandatory from day one regardless of how small your turnover is, because the platform is required to collect TCS against a valid GSTIN.
LegalDev's GST registration service is a common fit here, since it's built for exactly this kind of borderline case where an operator isn't sure they've crossed the threshold yet.
Monthly versus quarterly isn't really a free choice for everyone, it's tied to turnover. If your aggregate turnover exceeds Rs. 5 crore, monthly filing of GSTR-1 and GSTR-3B is mandatory. Below that threshold, you can opt into the QRMP scheme and file both returns quarterly, while still paying tax every month through a simplified challan based on either your last quarter's liability or a self-assessed amount.
Annual filing (GSTR-9, and GSTR-9C above Rs. 5 crore) isn't a choice at all in the sense of frequency, it's an additional yearly filing layered on top of whichever monthly or quarterly cycle you're already on.
If you're eligible for QRMP and deciding whether to opt in, weigh cash flow against convenience. Quarterly filing means less time on the portal, but you're still tracking tax liability every month for the challan payment, so the actual bookkeeping discipline required doesn't drop much. Businesses that want to share invoice data with buyers mid-quarter without waiting for the full quarterly filing can use the Invoice Furnishing Facility (IFF) to upload B2B invoices monthly even while staying on the QRMP cycle.
LegalDev can walk through your cash-flow pattern and tell you whether QRMP or monthly filing actually suits your business better, rather than picking whichever sounds simpler.
For a routine monthly or quarterly filing, the core document set is fairly consistent: sales invoices and any credit or debit notes issued during the period, purchase invoices and expense records, bank statements to reconcile what's hit your account against what you've reported, and your prior period's filed return for opening balances and carried-forward credit.
A few more items apply situationally, on top of this baseline. If you're moving goods over Rs. 50,000 in a single consignment, keep your e-way bill records handy. If your turnover crosses Rs. 5 crore, you're generating e-invoices with an IRN for B2B and export transactions, and that data should reconcile against what auto-populates in GSTR-1. An HSN or SAC-wise summary of your supplies is also expected on the return itself, so keeping your invoices coded correctly from the point of billing saves reconciliation time later.
Annual filings need more: audited financial statements where GSTR-9C applies, and a full year's GSTR-1 and GSTR-3B data to consolidate into GSTR-9. Keep this list current from month one rather than reconstructing it at deadline time; that's where most avoidable filing delays come from.
LegalDev's onboarding checklist for GST filing mirrors this exact document list, which is what new clients are asked for before their first filing cycle even starts.
Yes, and many do. As a service provider, GST registration becomes mandatory once your aggregate turnover crosses Rs. 20 lakh in a financial year (Rs. 10 lakh in special category states), and once registered, you're on the same GSTR-1 and GSTR-3B cycle as any other regular taxpayer, filing under your own name and PAN rather than a company structure.
Freelancers tend to have a simpler filing profile than product businesses: fewer invoices, usually all B2B or export-of-services, and minimal purchase-side ITC beyond software subscriptions, a laptop, or coworking space. That makes self-filing realistic if you keep basic records.
Two things trip up freelancers specifically. First, if you're providing services to overseas clients and receiving payment in foreign currency, that's an export of services, a zero-rated supply, and you'll want to look into filing a Letter of Undertaking (LUT) so you don't have to pay IGST upfront and then claim it back. Second, reverse charge liability applies to a narrow set of services, and it doesn't show up automatically on the portal; you have to self-declare it if it applies to your work.
LegalDev works with freelancers on both pieces, the LUT filing for export income and the ongoing GSTR-1/GSTR-3B cycle, so neither one gets missed.
The reliable approach is to log every invoice at the point of issue or receipt, not in a batch right before the deadline. Whether you're using a spreadsheet, Tally, Zoho Books, or another accounting tool, the fields that matter for GST are consistent: invoice number, date, GSTIN of the buyer or seller, taxable value, tax rate, and the HSN or SAC code.
If your accounting software integrates with the GST portal or supports the GSTR-1 offline JSON tool, invoice-level data can flow into your return with far less manual re-entry, which cuts down both time and the risk of a mismatch between your books and what you've filed.
On the purchase side, tracking now has an extra layer thanks to the Invoice Management System (IMS): every inward invoice your suppliers report needs an explicit accept, reject, or pending action before it counts toward your claimable ITC. Build a habit of checking that dashboard weekly rather than letting invoices pile up pending, since unclaimed or unreviewed invoices simply don't show up in your GSTR-2B when filing time comes.
LegalDev's GST filing clients get this same invoice-logging structure set up during onboarding, so tracking is in place before the first filing deadline arrives.
A late fee starts accruing automatically the day after the due date, no notice required. For GSTR-1 and GSTR-3B, it's Rs. 50 per day (split as Rs. 25 CGST and Rs. 25 SGST), capped based on your turnover slab. Nil returns filed late attract a lower Rs. 20 per day, capped at Rs. 500. On top of the late fee, unpaid tax accrues 18% annual interest calculated on the cash portion of your liability, from the day after the due date until you actually pay.
Beyond the direct cost, continued non-filing has knock-on effects. E-way bill generation gets restricted once returns are sufficiently overdue, which makes it hard to move goods at all. Persistent non-filers eventually risk GSTIN suspension. And since mid-2025, there's a hard three-year cutoff, GSTR-1, GSTR-3B, GSTR-4, GSTR-5 through 8, and GSTR-9 can no longer be filed at all once more than three years have passed from the original due date, so old pending returns aren't a "get to it eventually" problem anymore.
LegalDev's compliance team flags an approaching deadline days ahead of time for exactly this reason, so a late fee doesn't sneak up on a client.
For anyone beyond a handful of invoices a month, software wins on time and accuracy, not just convenience. Manual entry directly on the GST portal works fine for a low-volume nil or near-nil filer, but once you're tracking multiple invoices, HSN codes, and ITC reconciliation against GSTR-2B, doing it by hand raises the odds of a mismatch that now blocks your filing outright rather than getting quietly adjusted.
GST-integrated accounting software (Tally, Zoho Books, ClearTax, and similar tools) generates invoices with the right fields built in, prepares GSTR-1 data in the JSON format the offline tool accepts, and in many cases flags an ITC mismatch against your GSTR-2B before you even reach the portal. That's meaningfully different from catching the mismatch after the system has already rejected your GSTR-3B submission.
Manual filing still has its place for very small, low-transaction businesses where the cost of a software subscription doesn't justify itself. But the more your invoice count and ITC claims grow, the more software pays for itself in avoided errors and saved hours each month.
LegalDev's GST filing service runs this GSTR-2B check automatically on the client's behalf, so a mismatch gets caught before it ever reaches the portal.
No, GST registration is designed to be self-service. You can apply on the GST portal with your PAN, business address proof, bank details, and Aadhaar authentication, and for straightforward cases, especially individuals and sole proprietorships, approval typically comes through in three to seven working days.
Where an accountant or consultant genuinely helps is when your structure is more complex: a private limited company or LLP with multiple documents to align (incorporation certificate, MOA, board resolution, director KYC), a business operating in more than one state needing multiple GSTINs, or a case where you're not fully sure which category, goods versus services, normal versus composition scheme, applies to you. A wrong classification at registration stage can mean redoing filings later.
Professional fees for assisted registration are usually modest, often a few hundred to a couple of thousand rupees for a straightforward individual or proprietorship case, rising for companies with more documentation. If your situation is simple and you're comfortable with online forms, doing it yourself is a reasonable way to save that cost.
LegalDev's GST registration service is built for precisely these complex-structure cases, from LLP incorporation documents through to multi-state GSTIN applications.
Your first return follows the same mechanical steps as every return after it, but a few things are worth knowing specifically as a new filer. Once your GSTIN is active, log in to the GST portal, go to Services > Returns > Returns Dashboard, and select the financial year and the first tax period your registration covers, not necessarily the calendar month you applied in.
Start with GSTR-1 for that period, even if it's a nil return because you hadn't started billing yet. Enter or upload your sales invoice data, review the auto-populated summary, and file using DSC or OTP-based EVC. Then move to GSTR-3B: check your Invoice Management System dashboard first if you have any purchases to claim ITC on, since even a first-time filer's ITC claim is checked against GSTR-2B before the return will go through.
One nuance specific to new registrations: your very first period sometimes runs from your registration effective date rather than the 1st of the month, so double-check the exact period the portal is asking you to file for before entering data.
LegalDev walks first-time filers through this exact sequence as part of its GST registration and filing service, so nothing about the first cycle is guesswork.
GSTR-1 and GSTR-3B are the two returns nearly every regular taxpayer files every cycle, and they serve different purposes even though they're filed together.
GSTR-1 is the detailed return: every sales invoice, credit note, and debit note issued during the period, broken down by buyer. This is the data your customers rely on for their own input tax credit, since what you report here is what eventually shows up in their GSTR-2B. It's due on the 11th of the following month for monthly filers, or the 13th after quarter-end for QRMP filers.
GSTR-3B is the summary return: total outward tax liability, the input tax credit you're claiming, and the net tax payable in cash after adjusting that credit. Since mid-2025, GSTR-3B's outward-liability figures are pulled directly from your filed GSTR-1 and can't be edited inside GSTR-3B itself, so corrections now go through GSTR-1A, a same-period amendment window, before you file GSTR-3B. It's due on the 20th for monthly filers, or the 22nd or 24th for QRMP filers depending on your state category.
LegalDev's GST filing service manages both returns together every cycle, which keeps the GSTR-1-to-GSTR-3B handoff from becoming a source of errors.
A sole proprietorship doesn't get a separate legal identity under GST the way a company does, your GSTIN is issued against your own PAN, and you file returns as an individual running that business. Past that structural difference, the filing mechanics are identical to any other regular taxpayer: GSTR-1 and GSTR-3B on the same monthly or quarterly schedule, based on the same turnover thresholds for QRMP eligibility.
One thing that catches sole proprietors off guard is that if they run more than one proprietorship-style business under the same PAN in the same state, GST treats them as one aggregate turnover for threshold purposes, even if the businesses feel separate to the owner. If those businesses operate in different states, however, each state typically needs its own GSTIN and its own separate filing.
Personal liability is also worth flagging: since there's no distinct legal entity, GST dues, penalties, and interest attach directly to the proprietor personally, not to a company that could, in theory, be wound up separately from personal assets.
LegalDev registers sole proprietors directly against their PAN and manages the GSTR-1/GSTR-3B cycle from there, so the personal-liability side stays clearly understood from day one.
Yes, and a growing number of small businesses do exactly this. GST-focused software and portals can prepare your GSTR-1 data in the offline JSON format, auto-calculate tax liability, flag ITC mismatches against your GSTR-2B before you submit, and in some cases file directly through an API connection to the GST portal.
Where these tools actually replace a CA: routine data entry, invoice generation with correct GST fields, and basic reconciliation checks. Where they generally don't replace one: judgment calls. Deciding whether a particular expense falls under a blocked credit category under Section 17(5), handling a reverse charge situation correctly, structuring an export under LUT, or responding to a notice all benefit from someone who can interpret the law, not just apply a formula.
A practical middle path many businesses land on is using software for the monthly mechanical filing and bringing in a CA periodically, quarterly or at year-end, to review the books and catch anything the tool wouldn't flag on its own.
LegalDev's GST filing service runs on almost exactly this hybrid model, software-driven monthly filing backed by a professional review whenever a judgment call comes up.
The easiest system is the one you actually update in real time, not the most elaborate one. At minimum, keep a running log of every sales invoice and purchase invoice as it's issued or received, with the GSTIN, taxable value, tax rate, and HSN or SAC code captured at the time, not reconstructed later from memory or scattered WhatsApp messages.
A basic accounting tool, even a well-structured spreadsheet for very small operations, beats a shoebox of paper invoices every time, because GST filing needs that data in a structured, exportable form. If you're using invoicing software, check whether it can export directly in the GSTR-1 offline JSON format; that alone removes a large chunk of manual re-entry.
On the purchase side, build a weekly habit of checking your Invoice Management System dashboard rather than letting inward invoices sit unreviewed. An invoice you haven't accepted doesn't count toward your claimable credit, so a backlog there isn't just untidy, it's money sitting outside your GSTR-2B.
LegalDev sets up this same invoice-and-IMS logging structure for clients during onboarding, which removes most of the manual record-keeping burden from month one onward.
Filing follows registration, so the real question is when registration becomes mandatory, since filing obligations start the moment your GSTIN is active. For services, that threshold is Rs. 20 lakh aggregate turnover in a financial year (Rs. 10 lakh in special category states). For goods, it's Rs. 40 lakh in normal category states (Rs. 20 lakh in special category states).
Aggregate turnover is calculated on an all-India, PAN-wide basis, combining every GSTIN you hold and every branch under the same PAN, including exempt supplies and exports. It's not just your taxable sales in one state, which is a common miscalculation that leads businesses to believe they're under the threshold when they're not.
Certain categories bypass the turnover threshold entirely and must register (and therefore file) from the very first transaction: e-commerce sellers, casual taxable persons, non-resident taxable persons, and businesses making certain interstate supplies. If any of these apply to you, the turnover question doesn't come into play at all.
LegalDev's registration team calculates this PAN-wide turnover correctly the first time, which avoids the common mistake of thinking one state's sales alone decide the threshold.
Exports of goods and services are treated as zero-rated supplies under Section 16 of the IGST Act, meaning you don't charge GST on the export invoice itself, but you're still entitled to a refund of the tax paid on inputs and services used to fulfil that export. That's the core structural difference from domestic filing: exporters carry a refund process alongside their regular GSTR-1 and GSTR-3B cycle.
Most exporters choose to file a Letter of Undertaking (LUT) in Form RFD-11 at the start of each financial year, which lets them export without paying IGST upfront and then claim a refund of accumulated, unutilised input tax credit through Form RFD-01. The alternative route, paying IGST first and claiming it back through the shipping bill itself, ties refund processing to customs data and can return up to 90% provisionally within days, but it locks up working capital in the meantime.
Refund claims have to be filed within two years of the relevant date, and the LUT itself needs renewing every financial year before your first export invoice of that year goes out.
LegalDev assists exporters with both halves of this process, the annual LUT filing and the refund claim that follows it, so the two don't fall out of sync.
With Aadhaar authentication completed and no red flags in your application, GST registration is typically approved within three to seven working days from when you generate your Application Reference Number (ARN). A simplified route under Rule 14A can approve eligible small taxpayers, those with monthly output tax liability under a prescribed limit, in as little as three working days.
Without Aadhaar authentication, or if your application gets flagged for physical or biometric verification, the timeline extends considerably, sometimes up to 21 to 30 working days, since a tax officer needs to complete manual checks and, in some cases, a site visit.
If a tax official doesn't act on your application within the applicable window, the law provides for deemed approval, though relying on that as a strategy isn't advisable. The single biggest lever you control is document accuracy: mismatched addresses, unclear photo uploads, or inconsistent details across your PAN and application are the most common causes of delay or a Show Cause Notice, so getting the paperwork clean the first time is worth more than any other single step.
LegalDev's registration process is built around Aadhaar authentication specifically to land inside this three-to-seven-day window rather than drifting into manual verification.
A few mistakes come up repeatedly across new and experienced filers alike. Filing GSTR-3B without first checking that your GSTR-1 and GSTR-2B actually reconcile is one of the most costly, since the portal now blocks the filing outright if your ITC claim exceeds what's sitting in GSTR-2B, rather than letting you adjust it after the fact.
Treating pending IMS invoices as claimable is another frequent trap. An invoice sitting as "pending" in your Invoice Management System hasn't been accepted, and it won't count toward your GSTR-2B credit until you act on it.
Beyond the reconciliation-specific errors, watch for: entering the wrong GSTIN on an invoice (which denies your buyer their credit and can flag a mismatch on your side too), misclassifying HSN or SAC codes, forgetting to self-declare reverse charge liability on applicable purchases (it doesn't appear automatically), and letting an old, unfiled return drift toward the three-year cutoff after which it becomes permanently unfileable. Each of these is avoidable with a monthly review habit rather than a scramble on filing day.
LegalDev's GST filing service is built specifically to catch these mismatches and misclassifications before they turn into a blocked return.
Filing itself, the act of entering data and hitting submit, isn't difficult once you've done it a couple of times. The forms are structured, the portal walks you through the fields, and the actual data entry for a small business rarely takes more than an hour.
What's gotten noticeably harder over the past couple of years is the reconciliation layer sitting in front of that data entry. The Invoice Management System now requires an active decision on every inward invoice before it counts as credit. GSTR-3B's outward figures are locked and pulled from GSTR-1, correctable only through a same-period amendment window. And the ITC check against GSTR-2B has no override button anymore, a mismatch simply blocks the filing rather than letting you push through and fix it next month.
So the honest assessment: mechanically simple, procedurally exacting. A new business owner who builds the habit of weekly IMS reviews and monthly reconciliation will find filing manageable. One who treats it as a once-a-month afterthought is the one who hits a blocked filing on deadline day.
This reconciliation layer is exactly what LegalDev's GST filing service manages every cycle, so a client mostly only sees the parts of filing that actually need their input.
The fastest reliable route is Aadhaar authentication combined with a complete, accurate application on the first attempt. Applications verified through Aadhaar with no flags typically clear in three to seven working days, and eligible small taxpayers under Rule 14A can see approval in as little as three working days.
To keep it on the fast track: use business details that match your PAN and Aadhaar exactly, upload clear, legible address proof and photographs, avoid abbreviating or altering your business name across documents, and complete Aadhaar authentication as soon as the portal offers it rather than opting out. Opting out of Aadhaar authentication routes your application into manual or physical verification, which can stretch the timeline to 21 to 30 working days.
If a Show Cause Notice does come through asking for clarification, respond within the window given (usually seven working days) with exactly what's requested rather than resubmitting unrelated documents; a slow or incomplete response is what actually drags registration timelines out, more than the initial application itself.
LegalDev's registration team handles the Aadhaar authentication and document matching end to end, which keeps applications on this fast track rather than drifting into manual review.
It depends on where those businesses are located and how they're structured, not just on the fact that there are multiple of them. If you run more than one business under the same PAN within the same state, they're generally treated as one aggregate entity for GST purposes and typically fall under a single GSTIN, unless you specifically apply for separate registrations for distinct business verticals within that state, which GST law does permit in some cases.
If your businesses operate in different states, each state generally needs its own GSTIN, and each GSTIN files its own GSTR-1 and GSTR-3B independently, even though they might share the same PAN and the same owner. This means separate due dates to track, separate IMS dashboards to manage, and separate ITC pools, since credit under one GSTIN generally can't be used to offset liability under another.
Aggregate turnover for threshold purposes, though, is calculated across all GSTINs under the same PAN nationally, so you can't split a business across states purely to stay under the registration threshold in each location.
LegalDev can register and manage filings across more than one GSTIN for businesses operating in different states, keeping each state's cycle on its own track.
Before you hit submit on any GST return, run through this: sales invoices and any credit or debit notes for the period, fully entered or uploaded into GSTR-1. Purchase invoices reviewed and actioned (accepted or rejected) in your Invoice Management System, since pending ones won't count. Your GSTR-2B checked against what you're planning to claim as ITC, no exceptions, since the portal will block a mismatch outright.
Confirm your GSTR-3B's auto-populated outward figures actually match what you filed in GSTR-1, since they're now locked and pulled automatically, any correction needed has to go through GSTR-1A first. Check for any reverse charge liability on applicable purchases, since that doesn't populate automatically and needs manual self-declaration. If you're on the QRMP scheme, confirm your monthly challan payments are up to date even in a quarter where the return itself isn't due yet.
Finally: have your Digital Signature Certificate or OTP-EVC access ready, generate and pay any GST challan (Form PMT-06) for tax due, and download your filing acknowledgement once submitted, for your own records and for any future reconciliation.
LegalDev runs this exact checklist for clients before every submission, so nothing gets filed until the GSTR-2B reconciliation and IMS actions are actually clear.
Input tax credit only becomes claimable once it clears two checkpoints: your supplier has to have actually filed and reported the invoice, and you have to have explicitly accepted it in your Invoice Management System. Rejected or unactioned invoices simply don't flow into your GSTR-2B, the static monthly snapshot that determines what you can actually claim, regardless of what your GSTR-2A shows in real time.
Before filing GSTR-3B, compare what you intend to claim against your GSTR-2B directly. The portal enforces a hard match now, if your claimed ITC exceeds what's sitting in GSTR-2B, the filing gets blocked with no manual override available.
Not every input tax paid is claimable, either. Section 17(5) of the CGST Act blocks credit on a specific list regardless of how the invoice is coded, including food and beverages, club memberships, most passenger vehicle purchases, and personal-use expenses, among others. Claiming ITC on a blocked category, even briefly, tends to get flagged by the portal's automated scrutiny and can trigger interest and penalty on top of a mandatory reversal.
LegalDev's GST filing service checks every ITC claim against GSTR-2B before submission, specifically to keep a client's return from getting blocked at the last minute.
Once you submit GSTR-1, its data locks in for that period and flows through to your buyers' GSTR-2A and, after processing, their GSTR-2B, becoming their claimable credit. For GSTR-3B, once submitted and any tax due is paid through your challan, you get a filing acknowledgement, and the return status updates on the portal under Services > Returns > Track Return Status, searchable by your ARN or the relevant tax period.
Behind the scenes, your outward liability from GSTR-1 sits locked in GSTR-3B for the same period, and any correction needed from that point forward goes through GSTR-1A rather than a re-filing of GSTR-3B itself. The ITC you claimed reduces your electronic credit ledger balance, and the cash portion of your liability, if any, gets debited from your electronic cash ledger once the challan clears.
Practically, download your filing acknowledgement for your records. If you're expecting a GST refund or you've claimed a provisional amount tied to exports, that process runs separately and doesn't happen automatically just because your return is filed.
LegalDev shares the filing acknowledgement and ARN with clients directly after every submission, so there's always a record on hand for later reconciliation.
For monthly filers, GSTR-1 is due on the 11th of the following month, and GSTR-3B follows on the 20th. QRMP quarterly filers get slightly later dates: GSTR-1 by the 13th of the month after the quarter ends, and GSTR-3B by the 22nd or 24th, depending on your state category.
A few other returns run on their own schedules: CMP-08 for composition dealers is due by the 18th of the month after the quarter ends, GSTR-6 (Input Service Distributors) by the 13th of the following month, GSTR-7 (TDS) by the 10th, and GSTR-8 (e-commerce TCS) also by the 10th. Annual returns, GSTR-9 and GSTR-9C, are due by 31st December following the relevant financial year. ITC-04 for job work has a half-yearly or annual schedule depending on turnover.
CBIC does issue occasional one-off extensions, so treat any date you read in an article, including this one, as a starting reference rather than the final word; always cross-check against the GST portal's own compliance calendar closer to the deadline.
LegalDev keeps a client's filing calendar current against the GST portal's own compliance calendar, including any one-off CBIC extensions as they're announced.
Generally yes, as long as you're inside the three-year window from the original due date. Since mid-2025, the GST portal enforces a hard cutoff: GSTR-1, GSTR-3B, GSTR-4, GSTR-5 through 8, and GSTR-9 can no longer be filed at all once more than three years have passed from when they were originally due. Inside that window, the portal still lets you catch up, though every day of delay accrues the applicable late fee and 18% annual interest on any unpaid tax.
Before you catch up on old periods, check your GST portal notices section (Services > User Services > View Notices and Orders) for any GSTR-3A notices you may have received for missed filings; ignoring one for more than 15 days risks the officer moving to a best-judgment tax assessment under Section 62, which is a considerably worse position than filing the actual return yourself.
Filing older periods in the right order matters too. Since later returns often depend on figures carried forward from earlier ones, work through pending periods chronologically rather than jumping straight to the most recent one.
LegalDev can help catch up on pending periods in the correct chronological order and check for any outstanding GSTR-3A notices before starting.
Selling through a marketplace like Amazon, Flipkart, or Meesho changes your GST obligations from the ground up. Registration becomes mandatory the moment you start selling through the platform, regardless of turnover, because the marketplace is legally required to collect Tax Collected at Source (TCS) against a valid GSTIN under Section 52 of the CGST Act.
The marketplace deducts 1% TCS (typically 0.5% CGST plus 0.5% SGST, or 1% IGST for interstate sales) on the net value of your taxable supplies each month, deposits it with the government, and files its own return, GSTR-8, reporting what it collected against your GSTIN. That TCS amount lands in your electronic cash ledger and can be used to pay your own GST liability or claimed back as a refund if it exceeds what you owe.
For your own filing, treat marketplace sales like any other outward supply in GSTR-1 and GSTR-3B, but reconcile carefully: your GSTR-1 needs to show gross sales with returns and cancellations separately accounted, and it should be cross-checked against the marketplace's settlement report rather than assumed to match automatically, since a mismatch here is a common trigger for notices.
LegalDev registers e-commerce sellers for GST and reconciles the GSTR-8 TCS data against GSTR-1 every cycle, so marketplace settlements don't drift out of sync with what's filed.
Start with scope: does the quoted fee cover just GSTR-1 and GSTR-3B preparation and filing, or does it include IMS reconciliation, GSTR-2B matching, and responding to notices if one comes in? A low headline price that excludes reconciliation work often ends up costing more once those tasks get billed separately.
Ask how they handle a blocked filing. Given the current portal checks, a real, working answer, "we reconcile your GSTR-2B before the filing window opens" rather than "we'll fix it if it happens", tells you whether they're proactive or reactive about your compliance.
Ask about turnaround time relative to the due date, not just "how fast can you file," since filing on the 19th for a 20th deadline leaves no room to fix a blocked return. Ask whether they'll flag ITC that falls under Section 17(5) blocked credits before claiming it, since that's a common source of later notices. And ask what happens if a supplier hasn't filed on time and your ITC is affected as a result, since that's outside anyone's control but should still have a communicated process.
These are worth asking LegalDev, or any provider, before signing on, since the scope answer tells you more about the fee than the number itself does.
Once a startup crosses the applicable turnover threshold, or falls into a mandatory-registration category like e-commerce or interstate supply from day one, GST registration and filing follow the same rules as any other business. What's different for startups is usually the pace of change: turnover can jump quickly, funding rounds bring new complexity, and a business that was comfortably under the composition scheme threshold one quarter can outgrow it the next.
Early-stage startups with modest turnover sometimes benefit from the composition scheme, a simplified quarterly CMP-08 and annual GSTR-4 filing at a flat rate, with no ITC to reconcile, though this trades away input tax credit, which can matter if your supplier costs carry significant GST. Most growth-stage startups end up on the standard GSTR-1/GSTR-3B cycle once B2B sales, ITC claims, or interstate operations enter the picture.
Build the compliance habit early: a weekly IMS check, monthly reconciliation, and a real calendar reminder for due dates. A startup's first missed filing usually happens not from ignorance of the law but from nobody owning the task once the founder gets busy with everything else.
LegalDev works with early-stage startups on both the composition scheme and standard GSTR-1/GSTR-3B filing as they scale past the composition threshold.
Organise around the filing cycle, not around a generic filing cabinet. Keep sales invoices, purchase invoices, credit and debit notes, and bank statements sorted by tax period from the start, so that when the 11th or 20th of the month arrives, you're pulling an already-complete folder rather than assembling one under pressure.
A simple, workable structure: one folder or spreadsheet tab per GSTIN per month, containing outward supplies, inward supplies, the IMS action log (accepted, rejected, pending), and the GSTR-2B download for that period. Keep prior period returns accessible too, since opening balances and carried-forward ITC reference them.
If you're using accounting software, most of this organisation happens automatically as you issue and record invoices, which is a strong argument for adopting one even for a small operation. If you're working manually, a consistent naming convention (period, GSTIN, document type) saves far more time at filing than it costs to set up. Whatever the system, review it monthly rather than annually, so gaps surface while they're still easy to fix.
LegalDev sets clients up with this same period-and-GSTIN folder structure during onboarding, so the monthly review habit has somewhere organised to happen.
First, check exactly why. The portal now blocks a GSTR-3B filing outright, rather than accepting it with an error, mainly for one reason: your claimed ITC exceeds what's available in your GSTR-2B. If that's the case, go back to your Invoice Management System, review any invoices still marked pending, and accept the ones you're entitled to claim; your GSTR-2B updates and your claim should then fall within the allowed range.
If the issue is with GSTR-1 instead, most rejections there trace back to data errors, an invalid GSTIN entered for a buyer, a mismatched HSN code, or a formatting issue in a bulk-uploaded file. Correct the specific entry and resubmit; GSTR-1 doesn't carry the same hard block that GSTR-3B does, though errors discovered after filing need to go through GSTR-1A for correction.
If a digital signature or EVC verification step fails repeatedly, check that your registered mobile number and email are current on the portal, since OTP delivery issues are a common, easily fixed cause of failed submission that gets mistaken for a filing rejection.
LegalDev's filing team resolves GSTR-3B and GSTR-1 rejections as a routine part of its ongoing GST filing service, rather than treating each one as a separate emergency.
They're legally separate systems, different departments, different portals, different due dates, but they're increasingly cross-checked against each other in practice. GST returns report your sales, purchases, and indirect tax liability to the GST department; income tax returns (ITR) report your overall income to the Income Tax Department. A business typically owes both, and filing one doesn't substitute for the other.
Where they connect is reconciliation risk. Your turnover as declared in GSTR-1/GSTR-3B and GSTR-9 is visible to tax authorities and gets compared against the turnover you declare in your ITR and, where applicable, your tax audit report under Section 44AB. A significant, unexplained gap between your GST turnover and your income tax turnover is a common trigger for scrutiny from either department, since it suggests either underreported GST sales or underreported income.
Practically, this means your books should tell one consistent story across both filings. Businesses that treat GST and income tax as entirely separate bookkeeping exercises, reconciled only at year-end if at all, are the ones most likely to face a mismatch notice from one side or the other.
LegalDev's compliance team cross-checks these turnover figures for clients specifically to head off a scrutiny trigger before it happens.
The correction route depends on which return and how recently you filed it. For GSTR-1, if the corresponding GSTR-3B for that period hasn't been filed yet, you can amend invoice details through GSTR-1A, a same-period amendment window built specifically for this. Once GSTR-3B for that period is filed, further corrections to that GSTR-1 typically get carried into the GSTR-1 of a later period rather than reopening the original filing.
GSTR-3B itself doesn't allow manual edits to outward figures anymore, since those now come locked from GSTR-1. If something in GSTR-3B needs fixing after filing, whether liability or an ITC claim, the standard route is to make the correcting adjustment in a subsequent period's return rather than editing the original.
For annual returns, GSTR-9 has limited amendment scope once filed, and most corrections identified after the annual return get carried forward as adjustments in the following year's filings instead. Given how much depends on filing sequence and timing, if a correction involves a meaningful tax amount, it's worth getting a second opinion before deciding which route to use.
LegalDev handles GSTR-1A amendments and later-period corrections as part of its ongoing filing service, so a correction doesn't turn into a separate project.
Yes, filing is a legal requirement for every registered taxpayer, and it isn't optional based on whether there was business activity in a given period; even a zero-transaction period needs a nil return. Once you hold a GSTIN, the obligation to file continues until that registration is formally cancelled or surrendered.
The consequences escalate in stages. First comes the automatic late fee and 18% annual interest on any unpaid tax, accruing daily with no notice required. Continued non-filing restricts e-way bill generation, which makes it hard to move goods at all. Beyond a certain point, you'll receive a GSTR-3A notice giving you 15 days to file the pending return; ignore that window and the officer can move to a best-judgment assessment under Section 62, estimating your liability without your input, a distinctly worse position than filing yourself. Persistent non-compliance can lead to GSTIN suspension or cancellation. And once more than three years pass from a return's original due date, it becomes permanently unfileable, which can cascade into lost input tax credit for your buyers as well as your own compliance record.
LegalDev's GST filing service is built to keep clients ahead of this entire escalation, starting at the late fee stage rather than reacting once a GSTR-3A notice arrives.
For monthly filers, the recurring pattern through 2026 is GSTR-1 on the 11th of the following month and GSTR-3B on the 20th. QRMP quarterly filers file GSTR-1 by the 13th of the month after the quarter ends and GSTR-3B by the 22nd or 24th, depending on state category, while still paying tax monthly through a simplified challan.
Composition scheme dealers file CMP-08 by the 18th after each quarter and GSTR-4 annually. Input Service Distributors file GSTR-6 by the 13th of the following month, TDS deductors file GSTR-7 by the 10th, and e-commerce operators file GSTR-8, also by the 10th. Annual returns, GSTR-9 and GSTR-9C, fall due on 31st December following the financial year. ITC-04 for job work follows a half-yearly schedule, 25th October for the April-September period and 25th April for October-March, or annually if turnover is under Rs. 5 crore.
CBIC does issue occasional one-off extensions during the year, so treat these as the standing pattern rather than an unchangeable fixed calendar, and confirm the exact date against the GST portal closer to each deadline.
LegalDev keeps this calendar current for clients, including any CBIC extensions, as a standard part of its GST filing service.
LegalDev's compliance team handles your end-to-end GST return filings including GSTR-1, GSTR-3B, GSTR-9, GSTR-9C, and refund applications. Let our experts reconcile your GSTR-2B through the Invoice Management System (IMS) to maximize your ITC claims and keep your compliance spotless.