The 10th arrives, you send your sales data, and your accountant files GSTR-1. You assume the month is done. On the 21st you discover GSTR-3B is still pending and the late fee has started. GSTR-1 reports your sales invoices. GSTR-3B summarises those sales, sets off input tax credit and pays the tax. Filing one never covers the other.

That mix-up is common because both returns draw on the same invoices. They differ in purpose, timing and money. This guide covers the GSTR-1 vs GSTR-3B difference, due dates for monthly and quarterly filers, the right filing order and what a slip costs in rupees. Dates and fees below apply to FY 2026-27. CBIC sometimes extends deadlines, so check the GST portal before you file.

What is the difference between GSTR-1 and GSTR-3B?

GSTR-1 is a statement of outward supplies: every sale invoice, debit note and credit note in the period. GSTR-3B is a summary return where you declare liability, claim input tax credit (ITC) and pay the net tax. Put simply, GSTR-1 says what you sold, and GSTR-3B settles what you owe.

GSTR-1 also shapes what your customers can claim. Your invoices flow into their GSTR-2B, so a missed GSTR-1 stalls their ITC before it ever troubles you. GSTR-3B is the return where cash leaves your account. GSTR-1 is filed under Section 37 of the CGST Act and GSTR-3B under Section 39.

Other returns exist too. TDS deductors under GST file their own, which we explained in our note on GSTR-7 filing for GST TDS deductors. Composition dealers follow a different set (CMP-08 and GSTR-4), so this guide is for regular taxpayers.

What are the GSTR-1 and GSTR-3B due dates?

For monthly filers, the GSTR-1 due date is the 11th and the GSTR 3B due date is the 20th of the following month. Quarterly filers under the QRMP scheme file GSTR-1 by the 13th and GSTR-3B by the 22nd or 24th after the quarter ends. Madhya Pradesh falls in the group that files by the 22nd, but confirm your state's date on the portal.

Which businesses can use the QRMP scheme?

QRMP stands for Quarterly Return Monthly Payment. It is open to taxpayers with aggregate turnover up to ₹5 crore who opt in. You file returns quarterly but still pay tax monthly through challan PMT-06 by the 25th.

Should you choose monthly or quarterly filing?

Eligible doesn't mean better. Quarterly filing cuts 24 returns a year to 8, a real saving for a shop with few invoices. The catch is your buyers. Without the Invoice Furnishing Facility (IFF), which lets you upload B2B invoices in the first two months, they see your sales in GSTR-2B only after the quarter's GSTR-1. Many B2B suppliers stay monthly for that reason alone. If most sales go to consumers, quarterly is usually calmer. Anyone above ₹5 crore, or who hasn't opted in, files monthly by rule, as we explain in who must file GSTR-1 every month.

Which return should you file first, GSTR-1 or GSTR-3B?

File GSTR-1 first, check GSTR-2B second and file GSTR-3B last. That is the sensible GSTR-1 filing process because GSTR-3B now pulls its liability from your filed GSTR-1. Since the July 2025 tax period, a GSTN advisory dated 7 June 2025 has made that auto-populated liability non-editable, so you can't type over it.

If an invoice is wrong, correct it through GSTR-1A before filing GSTR-3B, or in a later month's GSTR-1. On the portal, go to Services, then Returns, then Returns Dashboard. GSTR-2B sits there too and lists the ITC your suppliers have made available.

Claim ITC from GSTR-2B, not from your purchase register alone. Missing supplier invoices are the usual reason the two don't match, and chasing them takes hours when your books are untidy. Steady accounting and bookkeeping support shortens that reconciliation a lot.

What happens if you file late or get it wrong?

Late filing costs ₹50 a day for a return with tax liability (₹25 CGST plus ₹25 SGST) and ₹20 a day for a nil return, under Section 47. The daily fee stops at ₹2,000 for turnover up to ₹1.5 crore, ₹5,000 up to ₹5 crore and ₹10,000 above that. Nil returns cap at ₹500. Interest of 18% a year applies to tax paid late under Section 50.

Here is an illustrative example, not a client record. A Bhopal trader owes ₹40,000 in net cash tax and files GSTR-3B 12 days late. The late fee is ₹600 and interest is about ₹237, so ₹837 in total. What changed afterwards was simple: he set an internal deadline of the 15th, five days before the real one, so a slow portal day no longer mattered.

Late returns carry quieter costs as well. The portal can restrict e-way bill generation once returns stay unfiled for a couple of periods, and it will not accept a return more than three years after its due date. A fee can't fix either.

Your monthly action plan, step by step

1. Close sales entries by the 5th and match your sales register with the invoices you raised.
2. Review B2B, B2C and credit note data, then file GSTR-1 by the 11th.
3. Open GSTR-2B once it generates, around the 14th, and compare it with your purchase register.
4. Hold back ITC for invoices your suppliers haven't reported. Claim it next month.
5. Pay the net tax after ITC set-off, then file GSTR-3B between the 15th and the 20th.
6. Save the ARN and payment challan. QRMP filers also pay through PMT-06 by the 25th in months one and two.

Noticed a gap in your filing routine?

If this made you realise your sales data and your GSTR-3B never quite line up, or that nobody in your business owns the 11th and the 20th, the gap is fixable. Our team prepares, reconciles and files both returns through our GST return filing service in Bhopal. Send a WhatsApp message with your last two months' figures and we'll tell you where you stand.

Frequently asked questions

Do I have to file GSTR-1 and GSTR-3B when I had no sales this month?

Yes. A month with no sales still needs a nil GSTR-1 and a nil GSTR-3B. Nil returns can be filed on the portal or by SMS from your registered mobile number. Skipping them costs ₹20 a day, capped at ₹500 per return, and six months of non-filing can put your registration at risk of cancellation.

Can I revise GSTR-3B after filing it?

No. GSTR-3B has no revision facility. If you under-reported tax or over-claimed ITC, you correct it in a later month's GSTR-3B, with interest where tax was short. If the error is in your sales data, GSTR-1A can fix it, but only before you file GSTR-3B for that period.

Do I need to file returns right after getting a GSTIN?

Yes. Returns fall due from the month your registration takes effect, even if you made no sales. A new GSTIN should come with a filing calendar from day one. If you haven't registered yet, our team can help with GST registration in Bhopal and set up your first return schedule.

Can I pay the GST late fee from my ITC balance?

No. Late fee must be paid in cash through the electronic cash ledger. The electronic credit ledger can offset tax, not fees. Interest also goes through cash. A late return therefore needs cash on hand, even when you hold plenty of unused credit.

Should the ITC I claim in GSTR-3B match GSTR-2B exactly?

Claim ITC only for invoices that appear in GSTR-2B and meet the conditions of Section 16 of the CGST Act. Claims outside 2B invite a notice. If a valid invoice is missing, hold it back and claim it once the supplier reports it, within the Section 16(4) time limit. The credit is delayed, not lost.

How old a GST return can I still file?

The GST portal does not accept a return more than three years after its due date, so a very old pending period may already be out of reach. Check how close your pending period is to that window. If it's still open, file it with the late fee and interest.