GST GST returns

GSTR-1 vs GSTR-3B: what is different and why they must match

GSTR-1 is the detailed list of your sales; GSTR-3B is the summary where you pay tax. The tax on sales in both should be the same for the period, and the portal flags you when it is not.

Updated 2026-11-054 min read

Who this is for

GST-registered businesses
Accountants and tax practitioners
Distributors with credit notes
Service providers taking advances
Owners checking returns

On this page 11

The two returns side by side

	GSTR-1	GSTR-3B
Purpose	Report sales	Declare summary, claim ITC, pay tax
Level of detail	Invoice-wise for B2B, summary for small B2C	Totals only
Purchases and ITC	Not reported	Reported in Table 4
Tax payment	None	Yes, credit and cash
Monthly due date	11th	20th
Who relies on it	Your buyers, for their GSTR-2B	Government, for tax collected

For the basics of each, see what is GSTR-1 and what is GSTR-3B.

Why the figures drift apart

Most gaps come from a handful of causes:

Credit notes shown in GSTR-1 Table 9B but not reduced in GSTR-3B, or the other way round.
Invoices added after GSTR-1 was filed, for example a sales bill entered late, then included in GSTR-3B but left for next month's GSTR-1.
Amendments to earlier invoices that change tax in the current period's GSTR-1.
Advances for services taxed in GSTR-3B but not shown in Table 11 of GSTR-1.
Typing totals by hand into GSTR-3B instead of using the pre-filled figures.
Wrong tax head: an invoice booked as CGST/SGST in the books but IGST in GSTR-1 because the state was corrected only on the portal.

A worked reconciliation

A Pune distributor finds this for November:

Item	Tax amount
Tax in GSTR-1 (invoices less credit notes)	₹2,46,600
Tax declared in GSTR-3B Table 3.1(a)	₹2,55,600
Difference	₹9,000

Tracing it: one credit note of ₹50,000 taxable at 18% (₹9,000 tax) was uploaded in GSTR-1 but the accountant typed GSTR-3B from the sales register, which had the credit note dated 1 December. The fix: correct the date in the books so that both returns agree, or carry the reduction in December's GSTR-3B. Here GSTR-3B overpaid ₹9,000, which can be adjusted in a later GSTR-3B within the law's time limits.

If the gap had gone the other way, with GSTR-3B lower than GSTR-1, it would mean tax short-paid, and interest would apply on the shortfall.

Monthly reconciliation method

Lock the month: no back-dated sales or credit notes after you start.
Take three totals: books (sales register plus credit and debit notes), GSTR-1 summary, and GSTR-3B draft.
Compare by tax head: IGST, CGST, SGST, cess. A gap in one head points to a state error.
Compare by table: B2B, B2C, exports, credit notes. A gap in one table points to a classification error.
List every difference with the invoice number and reason, and decide in which period it will be corrected.
Keep the working sheet. It saves hours at annual return time.

The purchase side: GSTR-2B and Table 4

GSTR-1 holds no purchase data, so the second reconciliation every month is between your own purchase register, your GSTR-2B, and the ITC claimed in GSTR-3B Table 4. Here too the system compares figures: if ITC claimed in GSTR-3B is more than what GSTR-2B supports, beyond a tolerance, an intimation can be issued asking you to reverse or explain the excess.

A simple rule keeps you safe: ITC claimed should be the eligible part of GSTR-2B, plus any credit genuinely carried forward from earlier months that has now appeared, minus reversals. Keep a running list of bills claimed in a later month, with the month they were booked and the month they were claimed. At year end, this list explains most of the difference between your books and the annual return.

What the portal does about mismatches

The GST system compares the two returns. If tax declared in GSTR-3B is lower than the tax in GSTR-1 beyond a tolerance, you can get a system intimation asking you to pay the difference or explain it, and further filing of GSTR-1 can be blocked until you respond. The auto-filled sales in GSTR-3B are also being locked more tightly to GSTR-1 and GSTR-1A, so corrections are expected at the GSTR-1 stage. Check current rules on gst.gov.in, because this area has changed several times.

This is general information, not tax advice.

Spotting gaps early with Cashflow OS

Because Cashflow OS builds both the GSTR-1 view and the GSTR-3B view from the same TallyPrime data, you can open them side by side for the same period and see where they differ. GSTR-1 tiles open the bill-wise list, so a stray credit note or a party with the wrong state shows up quickly. Corrections are made in Tally; filing stays on the GST portal.

Avoid these

Common mistakes

MistakeTyping GSTR-3B totals by hand from the sales register
Do this instead
Use the pre-filled figures from GSTR-1 and check them against the books instead of retyping.
MistakeCredit notes in GSTR-1 but not reduced in GSTR-3B
Do this instead
Make sure each credit note is dated and reported in the same period in both returns.
MistakeBack-dating sales after GSTR-1 is filed
Do this instead
Lock the month before reconciling; add late bills through the next GSTR-1 or GSTR-1A and match GSTR-3B.
MistakeCorrecting the state only on the portal
Do this instead
Fix the party's state in the books too, so the tax head is the same in books and returns.

Keep handy

Checklist

GSTR-1 vs GSTR-3B: what is different and why they must match — 7 checks. Tick them as you go.

Month locked against back-dated sales and credit notes
Books, GSTR-1 summary and GSTR-3B draft totals taken
Compared by tax head: IGST, CGST, SGST and cess
Compared by table: B2B, B2C, exports, credit notes
Service advances shown in both Table 11 and GSTR-3B
ITC in GSTR-3B Table 4 checked against GSTR-2B
Every difference listed with invoice, reason and period of correction

In Cashflow OS

How Cashflow OS helps

Cashflow OS puts your TallyPrime books on every phone in the team. Where it fits this topic:

Both views from the same data

Cashflow OS builds the GSTR-1 and GSTR-3B views from the same TallyPrime data, so you can open them for the same period and see where they differ.

See GST reports from your Tally data

Trace the gap bill by bill

GSTR-1 tiles open the bill-wise list, so a stray credit note or a party with the wrong state shows up quickly. Corrections are made in Tally; filing stays on the portal.

Questions people ask

Should GSTR-1 and GSTR-3B always match exactly?

For the same period, the tax on sales should match. Timing differences can be legitimate, but they should be explained and settled in a later period.

Which return should I fix if they differ?

Find which one is wrong compared with your books. Sales errors are fixed through GSTR-1A or later amendments; tax payment shortfalls through a later GSTR-3B with interest.

Does GSTR-1 affect my input tax credit?

No, your GSTR-1 affects your buyers’ credit. Your own credit comes from your suppliers’ GSTR-1, through your GSTR-2B.

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

For monthly filers, generally the 11th for GSTR-1 and the 20th for GSTR-3B. Dates can be extended, so confirm on gst.gov.in.

What happens if GSTR-3B tax is lower than GSTR-1?

You can get a system intimation to pay or explain the difference, and further GSTR-1 filing can be blocked until you respond. Interest applies on any shortfall.

Can I simply edit GSTR-3B to match my books?

Auto-filled sales in GSTR-3B are being locked more tightly to GSTR-1 and GSTR-1A, so corrections are expected at the GSTR-1 stage. Check current rules.

Is overpaid tax in GSTR-3B lost?

No. An overpayment can generally be adjusted in a later GSTR-3B within the law's time limits.

How often should I reconcile the two returns?

Every month. Small gaps are easy to trace when fresh and save a lot of work at annual return time.

This page is general information for Indian businesses, not tax, legal or financial advice. Rules and rates change — check the official portals or your CA before acting.