GSTR-3B is the return in which you work out and pay your GST for the period. It summarises your sales, your purchases under reverse charge and your input tax credit, and it ends with the tax you pay in cash. GSTR-1 reports the detail. GSTR-3B is where the money moves.
01Due dates
| You file | GSTR-3B is due |
|---|---|
| Monthly | 20th of the next month |
| Quarterly under QRMP, principal place of business in Gujarat, Maharashtra, Karnataka, Tamil Nadu, Kerala, Telangana, Andhra Pradesh, Goa, Madhya Pradesh, Chhattisgarh and some southern and western UTs | 22nd of the month after the quarter |
| Quarterly under QRMP, other states and UTs, mostly in the north and north-east | 24th of the month after the quarter |
The state groups are set by notification, as of October 2026, and the GST portal shows your own date on the dashboard. Quarterly filers also pay tax for the first two months of each quarter by the 25th through PMT-06. See the QRMP guide.
02The tables, in plain words
Table 3.1: sales and reverse charge purchases
This is the tax on your outward supplies: taxable sales, zero-rated sales such as exports, nil-rated and exempt sales, and non-GST supplies. It also carries purchases on which you pay tax under reverse charge.
The portal fills Table 3 from your GSTR-1. From the July 2025 tax period, these auto-filled figures cannot be edited in GSTR-3B. If they are wrong, you correct GSTR-1 through GSTR-1A before filing GSTR-3B.
Table 3.2: inter-state sales to unregistered buyers
Inter-state sales to consumers, composition dealers and UIN holders, shown by state. Getting the place of supply right here matters because it decides which state gets the tax.
Table 4: input tax credit
| Part | What it covers |
|---|---|
| 4A | Credit available: imports, reverse charge, credit from the Input Service Distributor and all other credit |
| 4B | Credit reversed, for example on blocked items or unpaid bills |
| 4C | Net credit, which is 4A less 4B |
| 4D | Other details, such as credit reclaimed after an earlier reversal, and ineligible credit |
The portal fills Table 4 from your GSTR-2B. You can still edit it, but claiming more credit than GSTR-2B shows is a common cause of notices.
Table 5: exempt and non-GST purchases
Purchases from composition dealers, exempt and nil-rated purchases, and non-GST items such as petrol and diesel. These carry no credit but must be reported.
Table 5.1: interest and late fee
The system works out interest on late payment and the late fee carried from a previous return. Interest can be recomputed on the portal if you think the figure is wrong.
Table 6: payment of tax
This is where credit is set off against tax, and the balance is paid in cash from your electronic cash ledger.
03A worked example
An electrical goods wholesaler in Delhi sells wires, switches and MCBs worth ₹12,00,000 in a month, all within Delhi, at 18%. Purchases from registered suppliers in the month carry ₹1,80,000 of GST, all of it showing in GSTR-2B.
| Head | Tax on sales | Credit used | Cash to pay |
|---|---|---|---|
| CGST | ₹1,08,000 | ₹90,000 | ₹18,000 |
| SGST | ₹1,08,000 | ₹90,000 | ₹18,000 |
| Total | ₹2,16,000 | ₹1,80,000 | ₹36,000 |
If the wholesaler also had ₹40,000 of IGST credit from inter-state purchases, that IGST credit would be used first against any IGST payable, then against CGST and SGST. CGST credit cannot pay SGST, and SGST credit cannot pay CGST. The CGST, SGST and IGST guide covers the order of set-off.
04Checks before you file
- Sales. Table 3.1 should match your sales register for the month, including credit notes.
- Credit. Table 4 should match GSTR-2B, less anything blocked or unpaid. Note where your books show a bill that GSTR-2B does not, and follow it up with the supplier.
- Reverse charge. Every reverse charge purchase should be in Table 3.1(d) and paid in cash.
- Cash balance. Pay the challan a day or two before the due date, so the money reaches your cash ledger in time.
- Nil return. If you had no sales, no purchases and no liability, you can file a nil return by SMS or on the portal.
05Records to keep each month
Keep a folder for every period with the GSTR-2B download, the purchase and sales registers you filed from, the matching sheet, the challan receipts and the filed return. A notice about a return from two years ago is answered from this folder, and an officer's first request is usually the working behind Table 4.
06When GSTR-3B is late
Interest at 18% a year runs on the tax paid late from cash, from the day after the due date. The late fee is ₹50 a day, or ₹20 a day for a nil return, capped at ₹2,000, ₹5,000 or ₹10,000 by turnover. The late fee and interest guide has the full table.
A late GSTR-3B can also block e-way bills after two missed periods, and repeated non-filing can lead to cancellation of registration.
07For larger firms
A Rajkot engineering company with three GSTINs in different states files a GSTR-3B for each GSTIN. Credit cannot be moved from one GSTIN to another through the return. Where the head office buys common services, an Input Service Distributor registration passes that credit to branches.
08If you find an error after filing
Correct it in the next return: add tax you missed, or reduce output tax through a credit note where the law allows. Interest applies to tax paid late.
This guide is general information as of October 2026 and does not amount to tax advice.
MatruOS shows the month's GST summary, with output tax and input credit side by side, before you sit down to file.