How to file GSTR-3B step by step: a month-end walk-through

The GST 3B return is a simplified summary return where you declare your outward liabilities and claim input tax credit (ITC). You must file it by the due date, even if you had no business activity. This is the filing walk-through for the accountant who closes the month. What each table holds is in the GSTR-3B meaning and format guide. Here we go in working order: before you open the form, the portal steps, what GSTR-2B has filled and what is still your call, payment, late fee and interest.

Before you open the form

1. Your own GSTR-1 is filed. GSTN says Tables 3.1(a), (b), (c), (e) and 3.2 are auto-drafted from GSTR-1/1A. If you save data in GSTR-3B before GSTR-1/1A is filed, those liability tables are not auto-populated.
2. GSTR-2B is generated and reconciled. It is generated on the 14th (how to download it). Match it to your purchase register first, using the 14th-to-20th plan. If you build the figures in Excel first, see the GSTR-3B working sheet.
3. IMS actions are done and 2B is recomputed. Pending invoices stay out of GSTR-2B and GSTR-3B. If you change an action, GSTN says you can recompute GSTR-2B at the time of filing and take the credit (how to recompute).
4. The previous return is filed. Section 39(10) bars a return for a period if an earlier period's return is not furnished, unless notified otherwise.
5. Cash is in the ledger. Reverse-charge tax, interest and late fee can be paid only from the electronic cash ledger, so deposit before you reach the payment screen.

Due dates

Monthly filers: the 20th of the next month (Rule 61(1)(i)), and the tax is due by the same date (Section 39(7)). Quarterly filers: the 22nd or the 24th of the month after the quarter, by State or Union Territory group, filing GSTR-3B for the last month of the quarter; for the first two months they deposit tax in FORM GST PMT-06 by the 25th (Rule 61(3)). Dates can be extended by notification (Section 39(6)), so check the current one.

The filing steps on the portal

The process on the GST portal involves generating the summary, checking the auto-populated figures, making payments, and filing with a digital signature or EVC. These steps follow GSTN’s own manual for GSTR-3B. Button names are as GSTN prints them.

1. Open the return. Log in and go to Services > Returns > Returns Dashboard. Select the financial year, quarter and period, click SEARCH, then click PREPARE ONLINE in the GSTR-3B tile.
2. Answer the questions. The portal asks a short questionnaire and shows only the tables that apply. Click NEXT.
3. Read the system generated GSTR-3B. The SYSTEM GENERATED GSTR-3B button gives a PDF of what GSTR-1/1A and GSTR-2B have filled in; GSTN says it is disabled if the monthly GSTR-1/1A is not filed.
4. Check liabilities (Table 3.1): Verify the auto-drafted outward supplies and reverse charge liabilities. These come from your GSTR-1.
5. Verify ITC (Table 4): Review the eligible and ineligible ITC auto-populated from your GSTR-2B. You do not need to enter all inward supply details, only the eligible and ineligible ITC amounts.
6. Work through the remaining tiles: 3.1.1, 3.2, 5 exempt, nil and non-GST inward supplies, and 5.1 interest and late fee for the previous period.
7. Click SAVE GSTR3B. GSTN warns that data entered but not saved can be lost or show as zero after you pay.
8. Download PREVIEW DRAFT GSTR-3B and read it. The PDF carries a DRAFT watermark because nothing has been set off yet.
9. Click PROCEED TO PAYMENT (Table 6). The system will offset your liabilities against your available ITC cash and credit balances. If there is a shortfall, click CREATE CHALLAN to pay the balance. Then click MAKE PAYMENT/POST CREDIT TO LEDGER. After this, GSTN says, you cannot change the return.
10. File. Click PROCEED TO FILE (or first TAX LIABILITY BREAKUP, AS APPLICABLE, which GSTN uses for the next return’s interest), tick the declaration, choose the authorised signatory and click FILE GSTR-3B WITH DSC or FILE GSTR-3B WITH EVC. For EVC, the OTP goes to the signatory’s registered email and mobile.
11. Download the filed return. The status changes to Filed and DOWNLOAD FILED GSTR-3B gives the final PDF (download guide).

What GSTR-2B pre-fills and what you still decide

The GSTR-2B to ITC guide has the full chain. GSTN lists Tables 3.1(d), 4(A)(1), 4(A)(3), 4(A)(4), 4(A)(5) and 4(B)(2) as auto-drafted from GSTR-2B, and says the auto-populated values are for assistance and the taxpayer must ensure they are correct. GSTN also says there is no invoice matching in GSTR-3B, so these checks are yours.

Paying: how credit and cash are used

GSTN’s manual says the set-off can be done only once in a tax period and not in part. Reverse-charge tax, interest and late fee are paid from cash only. IGST credit goes first against IGST, and what is left can pay CGST or SGST/UTGST in any order, before CGST or SGST/UTGST credit is used (Rule 88A). CGST credit cannot pay SGST, nor SGST credit CGST (Section 49(5)). The portal fills in an optimum split and lets you edit it.

Where monthly taxable supplies (other than exempt and zero-rated) exceed ₹50 lakh, Rule 86B limits credit to 99% of the output tax liability, so at least 1% goes in cash, with listed exceptions such as income tax paid above ₹1 lakh in each of the last two financial years.

Late fee and interest on GSTR-3B

Late fee is worked out by the portal from days late. GSTN’s manual gives ₹25 a day for a return with liability and ₹10 a day for a nil return, per Act (CGST and SGST), and no late fee on IGST or cess. Section 47(1) sets the base at ₹100 a day with a maximum of ₹5,000; Notification 19/2021-CT brings the maximum down for returns from June 2021 onwards:

The notification states the amounts under the Central Act, and GSTN charges the fee under the CGST and SGST Acts separately, so Table 5.1 shows both parts. Treat the table as a guide and check the figure the portal computes in Table 5.1 of the next period’s return.

Interest under Section 50(1) runs from the day after the due date at a rate not exceeding 18% a year, as notified. For tax on supplies of the current period, it is levied only on the part paid from the cash ledger; for earlier periods, on the full amount. Section 170 rounds the amount to the nearest rupee.

Nil GSTR-3B

Filing is mandatory even when there was no business in the period. GSTN allows the nil option only when nothing is auto-populated from GSTR-1/1A, IFF or GSTR-2B, you made no manual entries, and no interest or late fee is outstanding. Check the current GSTN advisory before using any other route.

Worked example: ITC and liability offset

A monthly filer with ₹1.2 crore turnover last year sold ₹10,50,000 of taxable goods this month. GSTR-1 was filed on 9 October and GSTR-2B was generated on 14 October. Figures are GST by tax head.

The arithmetic: ₹1,40,000 − ₹14,000 = ₹1,26,000. Cash is ₹1,92,000 − ₹1,26,000 = ₹66,000, made of ₹8,000 + ₹29,000 + ₹29,000. Supplies of ₹10,50,000 are far below ₹50 lakh, so Rule 86B does not apply. The ₹14,000 is not lost: once the supplier files and the invoices reach a later GSTR-2B, the trader can claim them within the Section 16(4) time limit.

Now the late version. Suppose the return is filed on 28 October, eight days after 20 October. The late fee is 8 × ₹25 = ₹200 under CGST and ₹200 under SGST, so ₹400 in all, well under the ₹1,000 maximum per Act for this turnover band. Interest on the ₹66,000 paid from cash cannot exceed ₹66,000 × 18% × 8 ÷ 365 = ₹260 (rounded), and the portal shows the exact figure. Both appear in Table 5.1 of the October period return and must be paid from cash.

Mistakes that cost money

• Typing the register ITC instead of the 2B figure. Editing Table 4A upwards turns the tile red, and it is the gap DRC-01C looks at.
• Paying before previewing and saving. After payment you cannot change the return, and after filing you cannot revise it.

Related guides

• Format of GSTR-3B tables explained
• GSTR 3B Table 11 adjustments for credit debit notes quarterly
• GSTR-3B October 2026 return deadlines and due dates
• Input tax credit reclaim procedure in GST: GSTR-3B steps
• GST notice Form DRC-01D: recovery under Rule 142B and how to file reply

Frequently asked questions

Last checked: 10 October 2026. Sources: GSTN manual: creation, saving, payment and filing of GSTR-3B, GSTN GSTR-3B FAQ, CGST Act, Section 39, Section 47, Section 50, Section 49, CGST Rules, Rule 61, Rule 88A, Rule 86B, Notification 19/2021-CT (late fee), GSTN DRC-01C advisory.