GSTR-1A for Marketplace Sellers: Correcting Sales Reported in GSTR-1 Before You File GSTR-3B

GSTR-1A is an optional GST form that lets you correct, or add to, the sales you reported in GSTR-1 for the same month, before you file GSTR-3B for that month. As of November 2026 the main rule is simple: file it after GSTR-1 and before GSTR-3B. It was reintroduced in July 2024 through CBIC notification 12/2024 dated 10 July 2024, according to ClearTax's explainer. The form is for the return you file yourself. It does not alter the statement your marketplace files, and we could not confirm any marketplace-specific version of it.

What is GSTR-1A?

GSTR-1 is your monthly or quarterly statement of outward sales. GSTR-1A is a companion form for changes to that statement. ClearTax describes it as a document containing changes made to sales invoices reported in GSTR-1, which can also add transactions you missed.

It is not mandatory. You use it only when you find a mistake. The GST portal's own guidance page was not readable when we checked, so the detail on this page comes from ClearTax and a second ClearTax explainer, not from the portal. Check the current rules on the portal or with your GST practitioner before relying on a date.

Who can file GSTR-1A?

According to ClearTax, any taxpayer who files GSTR-1 and GSTR-3B can use it, monthly or quarterly filers included. A nil GSTR-1 filer cannot. For marketplace sellers, that covers almost everyone with a regular GSTIN. Composition taxpayers cannot sell through an e-commerce operator at all, so they are not the audience here.

When can you file it, and what is the deadline?

GSTR-1A becomes available after you file GSTR-1 or after the GSTR-1 due date, whichever is later, and must be filed before the GSTR-3B due date for that period. ClearTax's own example: GSTR-1 for May 2025 filed on 10 June 2025 could be amended from 11 June until the GSTR-3B due date of 20 June 2025.

Another explainer gives the same shape: GSTR-1 is due by the 11th, the recipient's GSTR-2B is generated on the 14th, and GSTR-1A can be submitted until the taxpayer files GSTR-3B. Due dates can be extended by notification, so check the date for your month. There is no separate late fee for GSTR-1A because its time limit is tied to GSTR-3B.

What can you change with it?

All rows in the table are from ClearTax. Corrected values auto-populate in your GSTR-3B for that period, so you do not key them in twice.

Which marketplace errors does it help with?

Most marketplace sellers do not raise invoices one by one in GSTR-1; the data comes from marketplace tax reports or an uploaded file. Examples of the kind of error GSTR-1A could fix before GSTR-3B (our illustrations, not an official list):

1. A month's marketplace sales missing from the file you uploaded.
2. A product reported under the wrong GST rate. Check rates first in the GST rate finder.
3. A sale reported as within-state that was actually to another state, or the reverse. This also changes the CGST, SGST and IGST split.
4. Business-to-business invoices with a wrong buyer GSTIN. Note that GSTIN cannot be changed with GSTR-1A, so those need another route; ask your practitioner.

This is general information on how the form works, not a statement that the portal handles each case. The "marketplace invoice error" idea is ours. We could not confirm an official GSTR-1A step that applies only to marketplace-generated invoices.

Why do marketplace sellers need accurate GSTR-1 data at all?

Because your sales through a marketplace are reported twice: by you in GSTR-1, and by the operator in GSTR-8. Anyone supplying goods through an operator must be registered whatever the turnover, so every marketplace seller is in this system from the first order. CBIC's explainer says the operator collects tax on the net value of goods supplied through its portal and passes the rest to you. When your figures and the operator's differ, you are the one asked to explain. Catching the error inside the GSTR-1A window is cheaper than doing it after GSTR-3B.

A simple monthly habit: download the marketplace's sales and returns report for the month, total it by state, and compare it with GSTR-1 before the 11th. If the totals differ, find out why while GSTR-1A is still open.

Does GSTR-1A fix a TCS mismatch?

No. TCS comes from the marketplace's GSTR-8, which the operator files within 10 days after the month ends. Your GSTR-1 and that GSTR-8 are matched; a vendor summary of section 52 says unresolved differences can raise the supplier's output liability with interest.

If your TCS in the cash ledger is lower than your settlement report shows, the fix is with the marketplace and its GSTR-8, not GSTR-1A. Correct your own GSTR-1 where it is wrong, then raise a ticket with the marketplace. Background on TCS is in GST TCS on marketplace sales, and the credit steps are in how to claim TCS credit.

How does GSTR-1A work with IMS?

IMS, the Invoice Management System, went live on 14 October 2024, according to ClearTax. Buyers can accept, reject or hold invoices you report. If a buyer rejects an invoice or credit note, you can reflect the correction in GSTR-1A for the same period; amendments reach the recipient's GSTR-2B only in the following month. The same article lists e-commerce operator invoices under section 9(5) as one IMS category, but does not tie GSTR-1A to marketplaces. More in GST IMS for e-commerce sellers.

Step by step: how to use GSTR-1A

1. File your GSTR-1 (or wait until its due date passes).
2. Compare it with your marketplace settlement and tax reports for the month.
3. List each error: invoice, what is wrong, the correct value.
4. Open GSTR-1A on the GST portal and amend or add the entries. The portal's navigation may change, so follow its current prompts.
5. File GSTR-1A with your usual digital signature or EVC before the GSTR-3B due date.
6. Check that the corrected values appear in GSTR-3B, then file it.

If you have already filed GSTR-3B, GSTR-1A is closed for that month. Ask a chartered accountant about the next route. This page is general information, not tax advice. See also how fees and deductions hit a payout in Amazon seller fees in India.

FAQ

What is GSTR-1A in simple words? It is an optional form to fix or add to the sales you already reported in GSTR-1 for the same month. You can use it until you file GSTR-3B for that month.

Is GSTR-1A mandatory? No. It is optional. You file it only when you find an error in the sales you reported, or a sale you missed, and only before GSTR-3B for that month.

Is GSTR-1A only for e-commerce sellers? No. Any taxpayer who files GSTR-1 and GSTR-3B can use it. Marketplace sellers use it the same way as other sellers.

Can I file GSTR-1A after GSTR-3B? No. It must be filed before GSTR-3B for the same period. After that you need another route, so speak to your accountant.

Is there a late fee for GSTR-1A? ClearTax says no, because its deadline is tied to GSTR-3B. Late GSTR-1 and GSTR-3B filing still carry their own consequences.

Will GSTR-1A change the TCS my marketplace collected? No. TCS comes from the marketplace's own GSTR-8. A wrong figure there has to be sorted out with the marketplace.

When does the buyer see my correction? Input credit on the amended supplies appears in the recipient's GSTR-2B for the following tax period, not the current one, so a business buyer may see your correction a month later.

Next step

If every month you find GSTR-1 gaps against your Amazon or Flipkart reports, the root cause is usually the reports and the process, not the form. Blooprint's Amazon account management team can help you set up a cleaner month-end routine across marketplaces.