If you run a GST-registered shop, you file two regular returns: GSTR-1 and GSTR-3B. Many owners leave both to their accountant and only notice them when a notice arrives or a customer complains that their input tax credit is missing. Understanding the GSTR 1 vs GSTR 3B difference takes about ten minutes, and it helps you keep your billing data clean so that both returns tell the same story. This guide explains what each return reports, how the two are linked on the GST portal, why the numbers often do not match for retailers, and a simple monthly routine to reconcile them before filing.
This article is general information for shop owners, not tax advice. Due dates and portal rules change through notifications, so always confirm the current position on the GST portal or with your tax consultant.
GSTR 1 vs GSTR 3B difference at a glance
In one line: GSTR-1 is a detailed statement of your sales, while GSTR-3B is a summary return in which you declare your tax liability, claim input tax credit and pay the tax. GSTR-1 tells the system what you sold and to whom. GSTR-3B tells the system how much tax you owe for the period after credit, and it is the return through which that tax is actually settled.
| Point | GSTR-1 | GSTR-3B |
|---|---|---|
| What it is | Statement of outward supplies (sales) | Summary return of sales, input tax credit and tax paid |
| Level of detail | Invoice-wise for B2B sales, summarised for most B2C sales, plus credit/debit notes, HSN summary and document summary | Consolidated totals only, with no invoice list |
| Input tax credit | Not claimed here | Claimed here, based on your purchase records and GSTR-2B |
| Tax payment | No payment is made with GSTR-1 | Tax is paid from the cash and credit ledgers while filing |
| Effect on customers | Your B2B invoices flow into your customers’ GSTR-2B, which supports their credit | No direct effect on customers |
| Usual due date (monthly filers) | 11th of the following month | 20th of the following month |
What GSTR-1 reports
GSTR-1 is built straight from your sales bills. Think of it as the government’s copy of your sales register. For a typical retail or wholesale shop, the main sections are:
- B2B invoices: every invoice raised to a registered buyer, with their GSTIN, invoice number, date, taxable value and tax. This is the section your business customers care about most.
- B2C sales: sales to walk-in customers are usually reported as rate-wise and state-wise totals rather than bill by bill. Large inter-state B2C invoices above the notified limit are reported separately.
- Credit and debit notes: sales returns, rate differences and post-sale discounts that change the tax on an earlier invoice.
- HSN summary: quantity and value grouped by HSN code.
- Document summary: the invoice number series used in the period, including cancelled bills.
Because your B2B invoices feed into each buyer’s GSTR-2B, a late or wrong GSTR-1 hurts your customers, not just you. A wholesaler in Ernakulam who misses a retailer’s invoice in GSTR-1 will usually hear about it quickly, because the retailer cannot see that credit in their own statement. If you want to know what a billing system should export for this return, see our guide on GSTR-1 from billing software.
GSTR-1 for quarterly (QRMP) filers
Small taxpayers with aggregate turnover up to ₹5 crore can opt for the Quarterly Return Monthly Payment (QRMP) scheme. Under QRMP, GSTR-1 is filed once a quarter, and B2B invoices for the first two months can optionally be uploaded through the Invoice Furnishing Facility (IFF) so that buyers get their credit sooner. The GST portal’s QRMP FAQ explains the eligibility and dates.
What GSTR-3B reports
GSTR-3B is the return that settles your tax for the period. It has no invoice list. Instead, you (or the portal, as an auto-filled draft) enter totals:
- Outward supplies: taxable value and tax on your sales, plus zero-rated, nil-rated and exempt supplies, and inward supplies liable to reverse charge.
- Inter-state supplies to unregistered persons, composition dealers and UIN holders: shown state-wise.
- Eligible input tax credit: the GST on your purchases that you are entitled to claim, less any credit you must reverse.
- Exempt and non-GST inward supplies.
- Payment of tax: how the liability is set off against credit, and how much is paid in cash, along with any interest or late fee.
The credit side of GSTR-3B is where most of the money is. If you want a refresher on how credit works, read what is input tax credit in GST, with an example.
How the portal links the two returns
The GST portal pre-fills the sales liability in GSTR-3B from what you reported in GSTR-1 (or IFF), and pre-fills the credit side from your GSTR-2B. Corrections to sales already reported in GSTR-1 can be made through GSTR-1A for the same period, before GSTR-3B is filed. The GST Network has also made some auto-filled values non-editable in GSTR-3B. For example, under its advisories on Table 3.2, inter-state supplies to unregistered persons, composition dealers and UIN holders are taken from GSTR-1, GSTR-1A or IFF and have to be corrected there. In practice this means a mistake in GSTR-1 now flows straight into your tax payment, so getting the sales data right at the billing counter matters more than ever.
Due dates for GSTR-1 and GSTR-3B
The standard dates under the CGST Rules are:
- Monthly filers: GSTR-1 by the 11th of the next month, and GSTR-3B by the 20th of the next month.
- QRMP filers: GSTR-1 by the 13th of the month after the quarter (optional IFF by the 13th for the first two months). GSTR-3B is due by the 22nd of the month after the quarter for businesses whose principal place of business is in Kerala, Tamil Nadu, Karnataka and the other states listed in group one, and by the 24th for the states in group two. Tax for the first two months of the quarter is paid through a monthly challan.
You can check the GSTR-3B dates in Rule 61 of the CGST Rules on the CBIC tax information portal and in the GST portal’s GSTR-3B user guide. The government sometimes extends dates by notification, so treat the portal’s “Upcoming Due Dates” panel as the final word. Late filing attracts a late fee, and late payment of tax attracts interest.
Why GSTR-1 and GSTR-3B do not match for retailers
For a shop, the sales figure in GSTR-1 and the outward liability in GSTR-3B should agree for the period. When they don’t, it is almost always a process problem rather than a tax problem. These are the causes we see most often in retail and wholesale businesses.
1. Sales returns without a proper credit note
A customer returns goods, the counter refunds cash or adjusts the next bill, and the books show lower sales. But no credit note is reported in GSTR-1, so GSTR-1 still shows the full original sale. Every return that reduces tax needs a credit note linked to the original invoice. Our guide to debit note and credit note software for GST covers how to record these cleanly.
2. B2C totals taken from a different report
B2C sales are summarised in GSTR-1. If one person takes the total from the POS day-end report and another takes it from the accounts package, timing differences, voided bills and manual edits create gaps. Use one source, the GST sales register from your billing software, for both returns.
3. Month-end cut-off and late entries
A bill dated the 31st but entered on the 2nd, or a branch that sends its sales after GSTR-1 is filed, will show up in one return and not the other. Lock the period in your software once GSTR-1 is prepared.
4. Wrong rate, HSN or place of supply
An item master with the wrong GST rate, or an inter-state customer billed as local (CGST + SGST instead of IGST), changes the tax heads even when the total value is right. These errors usually start in the item or customer master, not at filing time.
5. Amendments, cancellations and advances
Cancelled invoices that were already uploaded, invoices amended after filing, and advances received for future supplies are handled differently in the two returns. If they are not tracked, the difference carries forward month after month.
A worked example (illustrative numbers)
Take a hardware shop in Thrissur that files monthly. For October, its billing software shows B2B sales of ₹4,20,000 and B2C sales of ₹6,35,000, a total taxable value of ₹10,55,000. During the month a contractor returned fittings worth ₹15,000 (taxable value), and the counter adjusted the amount against his next purchase. The accountant reduced sales in the books to ₹10,40,000 and used that figure as the GSTR-3B draft, but no credit note was reported in GSTR-1.
Result: GSTR-1 shows ₹10,55,000 and the books show ₹10,40,000, a gap of ₹15,000 in taxable value. At an assumed 18% rate used only for this illustration, the tax gap is ₹2,700. Since the portal now pre-fills GSTR-3B from GSTR-1, the cleaner fix is to issue the credit note against the original invoice and report it (through GSTR-1A for the same period or in the next GSTR-1, as your consultant advises), rather than overriding figures by hand. These numbers are made up to show the method. They are not benchmarks.
A monthly GSTR-1 and GSTR-3B reconciliation routine
You do not need a large accounts team to keep the two returns aligned. A shop owner or one trained staff member can follow this routine in under an hour each month.
- Close the billing period (by the 2nd or 3rd). Make sure every branch and counter has synced its bills, every sales return has a credit note, and cancelled bills are marked as cancelled, not deleted.
- Run the GST sales register. Export the period’s sales by rate, B2B/B2C and intra/inter-state from your billing software. This single report is the source for both returns.
- Check B2B details. Verify each B2B customer’s GSTIN and state. A wrong GSTIN means your customer loses credit, and you will spend time on corrections later.
- Prepare and file GSTR-1. Compare the GSTR-1 totals on the portal with your register before submitting. Check the HSN summary and the document summary (invoice series, cancelled count).
- Review the auto-filled GSTR-3B. Compare the pre-filled liability with the same register. If something is wrong, correct it at the source (GSTR-1A, or a credit/debit note), not by hand.
- Match purchases with GSTR-2B. Claim credit only for eligible invoices that appear in GSTR-2B, and follow up with suppliers whose invoices are missing.
- Keep a one-page reconciliation note. Record the GSTR-1 total, the GSTR-3B total, and an explanation for any difference. Next month you will start from a clean position.
If your shop also needs better GST reporting at the counter, our overview of GST billing software for retail shops in India lists what to look for.
How billing software reduces mismatches
Most mismatches start at the counter, so the fix also starts there. Good billing software should give you GST-ready invoices with HSN codes and correct tax heads, credit notes linked to the original bill, a GST sales register that both returns can use, and branch-wise data in one place. Caddayn Biller supports GST billing, barcode billing, inventory and multi-branch shops, so your sales data is organised before it reaches your accountant. You can download Caddayn and test it with your own item list and a sample month of bills.
Frequently asked questions
Can I file GSTR-3B before GSTR-1?
For the auto-fill to work and to avoid differences, file GSTR-1 (or IFF) first and then GSTR-3B for the same period. The portal pre-fills GSTR-3B from the sales you have already reported.
Is GSTR-1 required if I had no sales in the month?
Yes. A registered person has to file returns even for a period with no business, as a nil return. The GST portal allows nil filing for both returns, including by SMS for eligible taxpayers.
Do composition dealers file GSTR-1 and GSTR-3B?
No. Composition taxpayers follow a separate system (a quarterly statement and an annual return), so this comparison applies to regular taxpayers.
What happens if GSTR-1 shows more sales than GSTR-3B?
The department’s systems compare the two, and a persistent shortfall in GSTR-3B can lead to a notice asking you to pay the difference with interest or explain it. Reconcile every month and correct errors in the next eligible return.
Which return affects my customer’s input tax credit?
GSTR-1. Your B2B invoices reported in GSTR-1 or IFF appear in your customers’ GSTR-2B, which they rely on to claim credit.