What each return is for
| Item | GSTR-1 | GSTR-3B |
|---|---|---|
| What it holds | Every sale: B2B invoices one by one, B2C in summary, credit and debit notes, exports, HSN summary, documents issued | Totals: tax on sales, reverse-charge tax, input tax credit, interest and late fee |
| Who sees it | Your buyers: your B2B invoices reach their IMS and GSTR-2B | Only you and the department |
| Tax paid? | No | Yes, this is where you pay |
| Fix a mistake | GSTR-1A before GSTR-3B, or a later GSTR-1 | Liability comes from GSTR-1 and is locked |
GSTR-1 comes first. Its figures fill GSTR-3B. Your buyers’ credit depends on what you put in GSTR-1, so a late or wrong GSTR-1 hurts your customers too.
Due dates
| Return | Monthly filers | Quarterly (QRMP) filers |
|---|---|---|
| GSTR-1 | 11th of the next month | 13th of the month after the quarter |
| IFF (optional B2B invoices for months 1 and 2) | — | 1st to 13th of the next month, up to ₹50 lakh a month |
| GSTR-3B | 20th of the next month | 22nd or 24th of the month after the quarter, by state |
Sources: Notification 83/2020, rule 59 and rule 61. Due dates are sometimes extended for a month or a district, as for March 2026 GSTR-3B. Check the portal’s notices.
What lateness costs
Late fee. The CGST Act sets ₹100 a day, up to ₹5,000 (section 47). Notifications waive part of it: 19/2021 (GSTR-3B) and 20/2021 (GSTR-1) cap it for tax periods from June 2021, by turnover.
| Your case | Maximum late fee per return, CGST part |
|---|---|
| Nil return (nil tax in GSTR-3B, or nil sales in GSTR-1) | ₹250 |
| Aggregate turnover up to ₹1.5 crore last year | ₹1,000 |
| Aggregate turnover above ₹1.5 crore and up to ₹5 crore | ₹2,500 |
| Aggregate turnover above ₹5 crore | ₹5,000, the section 47 maximum |
The state GST law has its own late fee on top; the portal shows both when you file.
Interest. Section 50 charges interest on tax paid late, at a rate the government notifies, which the Act caps at 18% a year. For a return filed late, it is charged on the part paid from the cash ledger. The example below uses 18%; check the current notified rate.
Worked example. Kaveri Agencies has a turnover of ₹3 crore. Its September GSTR-3B shows ₹1,20,000 to pay in cash after credit, and it files on 30 Oct, ten days late.
- Interest at 18%: ₹1,20,000 × 18% × 10 ÷ 365 = ₹592.
- Late fee: charged for each day of delay; whatever the daily amount works out to, the CGST part cannot exceed ₹2,500 for this turnover. The state part is extra. The portal shows the exact figure.
- A late GSTR-1 also delays its buyers’ credit, which they notice in their GSTR-2B.
Try your own numbers with the free GST tools, or ask your CA.
What the portal locks now (2025–26)
| From | Change |
|---|---|
| Feb 2025 period | GSTR-1 Table 12 (HSN): pick codes from a list, separate B2B and B2C tabs |
| May 2025 period | Table 13 (documents issued) becomes mandatory |
| July 2025 period | Liability auto-filled into GSTR-3B from GSTR-1, GSTR-1A or IFF can no longer be edited in GSTR-3B; amend through GSTR-1A |
| Oct 2025 period | In IMS, credit notes can be kept “pending” for one tax period, and you can declare how much credit to reverse |
| November 2025 period | GSTR-3B Table 3.2 (inter-state supplies to unregistered persons, composition taxpayers and UIN holders) is locked too |
| 1 Dec 2025 | Returns more than three years past their due date are barred |
| Feb 2026 period | Portal fills the “tax liability breakup” for earlier periods and asks you to confirm it; CGST or SGST credit can pay IGST after IGST credit is used up |
| Apr 2026 | IMS offline tool (Excel) for bulk accept, reject or pending |
Coming, not yet in force. The 57th GST Council (8 Oct 2026) recommended waiving the late fee on GSTR-3B for businesses with turnover up to ₹5 crore in the previous year that file by the end of the month in which it was due, and a new mechanism to align GSTR-3B with GSTR-1 and GSTR-2B from the April 2027 return. Neither had been notified by 1 Nov 2026. Check the current notification. See the GST updates log.
A monthly routine that keeps both returns clean
- By the 5th: finish sales entries; cancel or credit-note any wrong invoices.
- By the 8th: check customers’ GSTINs and states, and the HSN summary.
- By the 11th: file GSTR-1. Fix anything in GSTR-1A, not in GSTR-3B.
- By the 14th: download GSTR-2B, act on IMS (accept, reject or pending), and match it with your purchase register.
- By the 20th: file GSTR-3B and pay the cash part.
How MyRecords helps
- Prepares GSTR-1 and GSTR-3B files for upload, computed from your submitted sales and purchase invoices. GSTR-1 covers B2B, large B2C, B2C summary, credit and debit notes, exports, nil-rated, the HSN summary with the B2B/B2C split, and documents issued. GSTR-3B covers tables 3.1, 3.2, 4, 5 and 6.1, checked against GSTR-1 and your GST ledger.
- Matches GSTR-2B with your purchases from the 2B file you download, and lets you make a bill from an unmatched row. Fetching 2B through a GSP is built and available once connected.
- Records your IMS decisions (accept, reject, keep pending) locally, with a worksheet to use on the portal. Sending them to the portal through a GSP is built and available once connected.
- Shows due dates for GST, TDS, PF, ESI, professional tax and advance tax on the home screen.
- Not yet: filing from inside MyRecords, quarterly (QRMP) returns, composition returns and GSTR-9 are on the roadmap. GSTR-1 advances (11A/11B), e-commerce supplies and amendments are added on the portal. Returns are worked out per company with one GSTIN; several GSTINs mean one company each.