GSTR-1 vs GSTR-3B: The Difference, and Why the Two Must Match

GSTR-1 lists what you sold, invoice by invoice. GSTR-3B is where you total the tax on those sales, set off your credit and pay the balance. They cover the same sales, so the tax in both should agree. When GSTR-1 shows more tax than GSTR-3B, the portal can ask you to pay or explain within seven days.

What is the difference, in one table?

If you want each return on its own, read what GSTR-1 is and what GSTR-3B is. This page is about how the two fit together.

How does GSTR-1 feed GSTR-3B?

You file GSTR-1 first. The portal then adds up the tax on those sales and fills it into Tables 3.1 and 3.2 of your GSTR-3B. Your credit comes from the other side: your suppliers' GSTR-1 builds your GSTR-2B, and GSTR-2B fills Table 4.

Can you still type over the sales figures in GSTR-3B? Here the sources do not agree. GSTN advisories reported in the tax press say the figures filled from GSTR-1 stopped being editable from the July 2025 return. The portal's own GSTR-3B manual, as read on 12 November 2026, still says auto-filled values can be edited. Plan for the stricter position. If a sales figure is wrong, correct it in GSTR-1A before you file GSTR-3B, and the right number flows in.

Why does the government care so much? Because your GSTR-1 hands credit to your buyers. If you report Rs 100 of tax there and pay Rs 80 in GSTR-3B, credit of Rs 20 exists that nobody paid for.

What does a mismatch trigger?

Rule 88C of the CGST Rules, in force since 26 December 2022, deals with one direction only: tax as per GSTR-1 (including GSTR-1A and the Invoice Furnishing Facility) being more than tax as per GSTR-3B for the same period.

• The intimation. The portal issues Part A of Form DRC-01B and emails a copy. The rule applies when the gap crosses an amount and a percentage recommended by the GST Council. One advisory firm reported the recommended limits as Rs 25 lakh and 20%, and noted that no notification had fixed them. Treat the trigger as not public.
• Your seven days. Pay the difference with interest through DRC-03 and give the payment reference in Part B, or explain the unpaid part in Part B. You can do a bit of both.
• If you do nothing. The amount can be recovered under section 79, the recovery provision, without a separate demand order. Rule 59(6) also stops you from filing the next GSTR-1 until you have paid or replied.

A gap too small for DRC-01B is not safe either. It shows up when your returns are scrutinised and again in your annual return.

What about the opposite case, GSTR-3B higher than GSTR-1? Rule 88C does not cover it. But you have paid tax on a sale your buyer cannot see, so the buyer gets no credit until you add the invoice to GSTR-1.

How do you check the two before filing?

1. Total your sales register for the period: taxable value and tax, by rate.
2. Open the GSTR-1 summary before you submit it. Compare it with the register, table by table. Remember to deduct credit notes.
3. File GSTR-1. If you spot an error after filing, use GSTR-1A before you touch GSTR-3B.
4. Open GSTR-3B and download the system-generated PDF. Check that Table 3.1 equals your GSTR-1 tax.
5. Match Table 4 with GSTR-2B, not with your purchase bills.
6. Once a quarter, compare the tax in all GSTR-1 against all GSTR-3B for the year so far. On the portal this is under Services, Returns, Tax liabilities and ITC comparison.

The first four steps take ten minutes a month. Do them before the 11th, not on the 20th.

A worked example: one invoice left out of GSTR-3B

You trade in electrical goods and file monthly. For May 2025, a period before the reported lock, your GSTR-1 showed sales of Rs 12,00,000 at 18%, so tax of Rs 2,16,000. While filing GSTR-3B you overwrote the figure with Rs 10,00,000 from an old working sheet and paid tax on that.

• Tax as per GSTR-1: Rs 2,16,000.
• Tax as per GSTR-3B: Rs 1,80,000.
• Short paid: Rs 36,000.

You find it on 20 December 2025 while tallying the year. The GSTR-3B was due on 20 June 2025, so the delay is 183 days.

• Interest: Rs 36,000 x 18% x 183/365 = Rs 3,249.
• Total to pay through DRC-03: Rs 39,249.

The interest runs on the full Rs 36,000. The relief that charges interest only on the cash portion applies to tax declared in a late return, not to tax left out of it. Had DRC-01B arrived first, the steps would be the same, with seven days on the clock. Keep the DRC-03 acknowledgement. You will need it when you prepare your annual return in GSTR-9.

The mistake people usually make

They prepare the two returns from two different sheets. GSTR-1 comes from the billing software on the 10th. GSTR-3B comes from a summary someone made on the 19th, after a credit note or a cancelled invoice changed the month. Each return looks right alone. Together they disagree.

Use one source. Whatever is in the filed GSTR-1, as corrected by GSTR-1A, is your sales figure for GSTR-3B. If the books say something else, fix GSTR-1.

Can you manage this yourself? If you raise a few dozen invoices a month, yes. If you sell on several marketplaces with daily returns and credit notes, the matching is where errors creep in, and a monthly review costs less than one notice.

Frequently asked questions

Read next