Filing GSTR-1, and Correcting It in GSTR-1A

GSTR-1 used to be the statement a business filed and then forgot. Its figures fed its customers’ credit, but its own tax was settled in GSTR-3B, where it could type whatever it chose. That gap has closed. GSTR-1 now fills in the liability in the business’s own GSTR-3B, and since the July 2025 tax period that liability can no longer be edited in GSTR-3B. A wrong figure in GSTR-1 now has to be corrected in GSTR-1, or in GSTR-1A before GSTR-3B is filed. Otherwise it is paid as reported.

This guide covers the procedure for both forms. The law is in section 37 of the CGST Act and explained in the conceptual guide GSTR-1 and GSTR-3B. Where GSTR-1 sits in the month is in the returns calendar.

What to have ready

• The sales register for the period (books): every tax invoice, bill of supply, revised invoice and export invoice, with the customer’s GSTIN where registered, place of supply, rate and tax.
• Credit and debit notes issued in the period (books), with the original invoice each relates to.
• E-invoice data (the Invoice Registration Portal, through the GST portal), for a supplier required to e-invoice. It populates several tables automatically.
• Advances received without an invoice in the same period, and advances adjusted against invoices (books).
• An HSN-wise summary (books, or the e-invoices), split between supplies to registered and unregistered persons, with quantity and unit for goods.
• The serial number ranges of documents issued (books): invoices, credit and debit notes, receipt, payment and refund vouchers, delivery challans, with cancelled numbers.
• Supplies through e-commerce operators (books and the operator’s statements), with the operator’s GSTIN.
• Corrections to earlier periods (books, checked against earlier GSTR-1s on the portal).
• Customer actions in IMS (portal, the supplier view of the Invoice Management System), which show records customers have rejected.
• The previous period’s GSTR-3B, already filed (portal). Without it the portal will not accept this GSTR-1.

What rule 59 requires

Rule 59(1) requires the details of outward supplies to be furnished in FORM GSTR-1 for the month or the quarter. Rule 59(4) sets the level of detail:

• invoice-wise details of all supplies, inter-State and intra-State, to registered persons
• invoice-wise details of inter-State supplies to unregistered persons where the invoice value is more than Rs 1 lakh
• consolidated details, rate-wise, of intra-State supplies to unregistered persons, and State-wise of inter-State supplies to unregistered persons up to Rs 1 lakh
• debit and credit notes issued during the period for earlier invoices

The Rs 1 lakh threshold replaced Rs 2.5 lakh from 1 August 2024 (Notification No. 12/2024-Central Tax). The copy of FORM GSTR-1 published on CBIC’s site still shows Rs 2.5 lakh, but the portal’s user manual applies Rs 1 lakh from the August 2024 return period.

QRMP taxpayers may report supplies to registered persons for the first two months of a quarter through the Invoice Furnishing Facility under rule 59(2), and those details are then left out of the quarterly GSTR-1 (rule 59(3)). That facility is covered in the QRMP guide.

The tables, and what goes where

The portal presents GSTR-1 as a set of tiles, one for each table. The portal’s GSTR-1 user manual describes them as follows.

Supplies to registered persons: tables 4A, 4B, 6B and 6C (B2B). Invoice by invoice, including supplies on which the recipient pays reverse charge (4B), supplies to SEZ units and developers (6B) and deemed exports (6C). These are the records that reach the customer’s IMS and GSTR-2B. A wrong GSTIN here means the customer cannot take the credit.

Large inter-State supplies to unregistered persons: tables 5A and 5B (B2CL). Invoice by invoice, for invoice values above Rs 1 lakh, with the place of supply.

Exports: table 6A. Invoice by invoice, with the shipping bill or bill of export number and date. The form’s instructions allow the invoice to be reported first and the shipping bill details added later through the amendment table, “before claiming any refund”. Exports under bond or letter of undertaking are reported with nil tax.

Other supplies to unregistered persons: table 7 (B2CS). Consolidated by rate, and for inter-State supplies by State, net of credit and debit notes.

Nil-rated, exempt and non-GST supplies: table 8. Split between inter-State and intra-State supplies, and between registered and unregistered recipients.

Credit and debit notes: table 9B. Separately for registered recipients (CDNR) and unregistered recipients (CDNUR), each linked to the original invoice.

Amendments: tables 9A, 9C, 10 and 11. Table 9A amends B2B, B2CL and export invoices of earlier periods. Table 9C amends earlier credit and debit notes. Table 10 amends B2CS figures. The second part of table 11 amends advance details.

Advances: table 11. Tax on advances received without an invoice in the period (11A), and the adjustment of earlier advances against invoices now issued (11B).

HSN-wise summary: table 12. Described below.

Documents issued: table 13. Described below.

E-commerce supplies: tables 14 and 15. Table 14 reports supplies made through an e-commerce operator who collects tax under section 52 or pays tax under section 9(5). Table 15 is filled by the operator for supplies on which it pays tax under section 9(5). These were added by Notification No. 26/2022-Central Tax and went live on the portal from the January 2024 tax period (GSTN advisory of 15 January 2024).

HSN in table 12: the current requirement

The number of HSN digits is fixed by Notification No. 12/2017-Central Tax, as amended by Notification No. 78/2020-Central Tax from 1 April 2021, issued under the proviso to rule 46:

Aggregate turnover in the preceding financial year	HSN digits
Up to Rs 5 crore	4
More than Rs 5 crore	6

The notification lets a person with turnover up to Rs 5 crore omit the HSN code on invoices to unregistered persons. Instruction 18 to FORM GSTR-1 ties table 12 to the same notification.

The portal has enforced this in phases. Phase 2 applied from 1 November 2022. Phase 3 applies from the May 2025 return period (GSTN advisory of 1 May 2025, with the detailed advisory of 25 April 2025). Its main features are:

• No manual entry. The HSN code is chosen from a drop-down, and a “Description as per HSN Code” fills itself from the HSN master.
• Two tabs. Table 12 is split into “B2B Supplies” and “B2C Supplies”, reported separately.
• Value checks. The B2B tab is checked against the B2B values in tables 4A, 4B, 6B, 6C, 8, 9A, 9B, 9C, 15 and 15A. The B2C tab is checked against the B2C tables. Only differential values count for amendments. At present these checks give a warning and do not stop filing, but the B2B tab cannot be left empty if B2B supplies appear elsewhere in the form.
• B2C is lighter. The B2C tab is not mandatory, and the portal currently accepts any figure in it.

GSTN has said Phase 4 will be “communicated in due course”; no later advisory has announced it. The portal manual also describes an IMPORT HSN DATA FROM E-INVOICES button that fills table 12 from the supplier’s e-invoices.

Table 13 is mandatory

Table 13 lists the documents issued during the period by type: invoices for outward supply, invoices for inward supply from unregistered persons, revised invoices, debit notes, credit notes, receipt vouchers, payment vouchers, refund vouchers and four kinds of delivery challan. For each type it gives the serial numbers from and to, the total, the number cancelled and the net issued. Rule 48(3) is the source of the requirement to furnish invoice serial numbers in GSTR-1.

From the May 2025 return period the portal will not file a GSTR-1 or GSTR-1A that reports B2B or B2C supplies with table 13 blank (GSTN advisory of 25 April 2025).

E-invoices fill the form

A registered person notified under rule 48(4) prepares its invoices by uploading them to the Invoice Registration Portal and obtaining an Invoice Reference Number. Notification No. 10/2023-Central Tax extended this to those with aggregate turnover above Rs 5 crore from 1 August 2023. Under rule 48(5), an invoice that should have been an e-invoice but was not “shall not be treated as an invoice”.

The GST portal takes the e-invoice data from the IRP and puts it in the supplier’s GSTR-1. According to the portal’s GSTR-1 FAQs, it fills:

• tables 4A, 4B, 4C, 6B and 6C (B2B invoices)
• table 6A (export invoices)
• table 9B (credit and debit notes, registered and unregistered)

B2CS supplies, advances and nil-rated supplies are not e-invoiced and are entered by the supplier. The auto-populated records can be edited before filing. When one is edited, the portal clears its Source, IRN and IRN Date fields. The DOWNLOAD DETAILS FROM E-INVOICES (EXCEL) button gives a file of everything populated.

Since 1 April 2025, a taxpayer with aggregate annual turnover of Rs 10 crore or more cannot report an e-invoice to the IRP more than 30 days after the document date. The IRP rejects it (GSTN advisory of 5 November 2024). An invoice that misses that window never reaches GSTR-1 automatically.

The due date, and the order of filing

Section 37(1) fixes the tenth of the following month, but Notification No. 83/2020-Central Tax has extended it, from 1 January 2021, to the 11th for monthly filers and the 13th of the month after the quarter for QRMP filers.

Can GSTR-1 be filed after GSTR-3B? For the same period, no. Section 39(10) bars a GSTR-3B for a tax period if the GSTR-1 for that period “has not been furnished”. So the GSTR-1 for September must be filed before the GSTR-3B for September. For the next period the rule runs the other way. Rule 59(6)(a) bars a monthly filer’s GSTR-1 if it “has not furnished the return in FORM GSTR-3B for the preceding month”, and rule 59(6)(b) does the same for a QRMP filer. Section 37(4) adds that no GSTR-1 can be filed while an earlier one is outstanding. Rule 59(6) also blocks GSTR-1 where bank account details under rule 10A are missing, or where an intimation under rule 88C or rule 88D has been neither paid nor answered.

Filing on the portal

The portal’s GSTR-1 user manual sets out these steps:

1. The taxpayer logs in and goes to Services > Returns > Returns Dashboard, selects the financial year, quarter and period, and clicks SEARCH.
2. In the GSTR-1 tile, PREPARE ONLINE opens the form on the portal. PREPARE OFFLINE uploads a JSON file prepared with the offline tool.
3. Where e-invoices have been issued, their details are already in the relevant tables and can be downloaded in Excel to check them.
4. Each table is opened from its tile, and records are added with ADD RECORD or corrected with AMEND RECORD. Table 12 records can be imported from e-invoices.
5. The taxpayer clicks GENERATE SUMMARY, then PROCEED TO FILE/SUMMARY to view the consolidated summary.
6. FILE STATEMENT, followed by FILE WITH DSC or FILE WITH EVC, files the statement. The portal issues an acknowledgement reference number and sends an SMS and email to the primary authorised signatory.

A nil GSTR-1 is filed by generating the summary and filing without entering data. It can also be filed by SMS, covered in the guide on nil returns.

Signing

Rule 26(1) requires the statement to be submitted with a digital signature certificate, through e-signature, or “verified by any other mode … notified by the Board”. Notification No. 6/2017-Central Tax notifies verification by electronic verification code. The proviso that once required companies to use a DSC was omitted with effect from 1 November 2021 (Notification No. 32/2021-Central Tax). The portal’s GSTR-1 FAQs now state that “DSC is not mandatory for any class of taxpayer”. The EVC goes to the registered mobile number of the primary authorised signatory. A DSC must be PAN-based, current and registered on the portal. Rule 26(2) names who signs: for a company, its chief executive officer or authorised signatory; for a firm, a partner or authorised signatory; for an individual, the individual.

GSTR-1A: the second chance before GSTR-3B

Notification No. 12/2024-Central Tax inserted a proviso to rule 59(1). It lets a person who has furnished GSTR-1 for a period, “but before filing of return in FORM GSTR-3B for the said tax period, at his own option, amend or furnish additional details” in FORM GSTR-1A. Rule 59(4A) lists what it may contain, which mirrors rule 59(4). It was first available in August 2024, for the July 2024 period (GSTN advisory of 26 July 2024).

The window. For a monthly filer, GSTR-1A opens on the later of the GSTR-1 due date (the 11th) and the date the GSTR-1 is actually filed. It stays open until the GSTR-3B for that period is filed. For a QRMP filer it opens quarterly, on the later of the 13th and the date the quarterly GSTR-1 is filed. It has no due date of its own. Once the GSTR-3B is filed, it is closed for that period (portal GSTR-1A FAQs).

What it can and cannot do. According to the portal’s GSTR-1A FAQs and the form’s instructions:

• It adds records missed from the period’s GSTR-1, or amends records reported in it, including credit and debit notes.
• A QRMP filer can use it to amend records reported through IFF in the first two months of the quarter. There is no other facility to amend IFF records during the quarter.
• It cannot change the recipient’s GSTIN. That correction goes only in a GSTR-1 for a later period.
• It cannot amend records of earlier periods. Those go in the amendment tables of a later GSTR-1.
• It can be filed only once for a period, and there is no nil GSTR-1A.
• If a record is saved in GSTR-1A but the form is not filed, the portal will not let the GSTR-3B be filed. The saved record must be filed, deleted or reset first.
• The form’s instructions describe it as “an optional form without levy of late fees”.

The effect. The net of GSTR-1 and GSTR-1A fills the liability tables of the same period’s GSTR-3B. For the customer, rule 60(7)(iia) puts the GSTR-1A details in the GSTR-2B of the period in which they are filed. The GSTN advisory states that the credit “will be available to the recipient in FORM GSTR-2B generated for the next tax period”.

Why it now matters more. GSTN made the liability auto-populated from GSTR-1, GSTR-1A and IFF non-editable in GSTR-3B from the July 2025 tax period (advisory of 7 June 2025). It did the same for table 3.2 inter-State supplies from the November 2025 period (advisory of 5 December 2025). In both advisories the stated route for a correction is GSTR-1A, before GSTR-3B is filed. The portal’s GSTR-3B user manual and FAQs have not been revised to match and still describe these values as editable.

Late fee

Section 47(1) imposes a late fee of Rs 100 a day, up to Rs 5,000, for a GSTR-1 not furnished by the due date. The State GST Acts carry a parallel section 47. Notification No. 4/2018-Central Tax, as amended by Notification No. 20/2021-Central Tax, waives the central fee above these amounts, for periods from June 2021:

Class	Fee per day (central tax)	Maximum (central tax)
Nil outward supplies in the period	Rs 10	Rs 250
Aggregate turnover up to Rs 1.5 crore	Rs 25	Rs 1,000
Over Rs 1.5 crore and up to Rs 5 crore	Rs 25	Rs 2,500
Over Rs 5 crore	Rs 25	Rs 5,000 (section 47)

Interest does not arise on GSTR-1 itself. It arises on tax paid late in GSTR-3B, covered in the GSTR-3B guide.

What can be changed after filing

A filed GSTR-1 cannot be revised. Before the period’s GSTR-3B, it is corrected in GSTR-1A. After that, an error or omission is corrected in the amendment tables (9A, 9C, 10, 11) of a later GSTR-1, under section 37(3). The proviso to section 37(3) allows no rectification after 30 November following the end of the financial year, or after the annual return is filed, if earlier. Section 37(5) bars filing a GSTR-1 at all more than three years after its due date.

The courts have relaxed the 30 November limit for bona fide errors that cause no loss of revenue. In Aberdare Technologies Pvt Ltd v Central Board of Indirect Taxes and Customs (Bombay High Court, 29 July 2024), the petitioners had filed their returns in time and found errors in December 2023, after the deadline. The State did not dispute that there was no loss of revenue. The court followed its earlier decision in Star Engineers and directed that the portal be opened for the petitioners to amend GSTR-1 and GSTR-3B, or that a manual application be accepted. The Supreme Court dismissed CBIC’s special leave petition on 21 March 2025 (SLP © Diary No. 6332 of 2025), calling the judgment “just and fair, as there is no loss of revenue”. It said that the Bar Code India (Punjab and Haryana) and Yokohama India (Telangana) decisions, which had refused such relief, “prima facie, do not lay down good law”. The order is as reproduced in later High Court judgments, including Issar Industries (Delhi, 27 May 2025). The scope of this line, and how it is now applied, is covered in correcting mistakes in returns.

The procedure in order

1. File the previous period’s GSTR-3B, and confirm bank details and any rule 88C or 88D intimation are cleared.
2. Reconcile the sales register with the e-invoices the portal has populated.
3. Enter B2B, B2CL, export, B2CS, nil-rated, credit and debit note, advance and amendment details in their tables.
4. Fill table 12 by HSN from the drop-down, separately for B2B and B2C, and table 13 with document serial numbers.
5. Generate the summary, check it, and file with DSC or EVC by the 11th, or the 13th for a quarter.
6. Review the supplier view of IMS for records customers have rejected.
7. Correct the period’s errors through GSTR-1A before filing GSTR-3B. Correct earlier periods’ errors in a later GSTR-1 before 30 November after the year.

The next guide covers the customer’s side: the Invoice Management System, and the GSTR-2B it produces.