How to Prepare GSTR-1 from Marketplace Sales Reports (2026 Guide)
Updated 11 October 2026 · 5 min read
Marketplace sellers file GSTR-1 from data scattered across Amazon, Flipkart, Meesho and their own registers. Preparing the B2B, B2CS and HSN summaries by hand is slow and easy to get wrong. Here is how to build the file in one pass instead.
Collect the reports
Download the Amazon MTR, the Flipkart and Meesho sales reports, or your own sales register, as CSV or Excel. One month per filing works best.
Enter your GSTIN and period
In the GSTR-1 tool, enter your GSTIN and the filing period so the JSON carries the correct header for the portal.
Drop in the files
Entrifix reads each report, maps its columns, validates GSTINs with checksum, splits IGST versus CGST and SGST by place of supply, and snaps tax rates to the standard slabs.
Review, then export
Check the B2CS totals by state and rate, the B2B invoices and the HSN summary. Fix any flagged issues, then download the GST portal JSON and a summary spreadsheet for your records.
B2B versus B2CS: why the split matters
Sales to buyers with a valid GSTIN go into B2B, invoice by invoice, because the buyer claims input credit against them. Sales to consumers or unregistered buyers roll up into B2CS by state and rate. Mixing the two is one of the most common reasons a GSTR-1 draws a mismatch notice.
Entrifix makes the split from the buyer GSTIN on each row, and computes the intra-state or inter-state type from your GSTIN's state code against the place of supply.
Checks worth doing before you file
- Every buyer GSTIN passes the checksum - invalid GSTINs are flagged per row.
- Tax amounts match the rate applied on the taxable value; mismatches are listed with the row reference.
- Refunds and cancellations reduce the period's totals instead of adding to them.
- HSN summary totals agree with the B2B and B2CS totals.
What is not included yet
The marketplace tax-collected-at-source section (Table 14) is not part of the tool today. If TCS applies to you, capture it separately in the portal for now.
Common questions
Amazon: the Month-wise Transaction Report (MTR). Flipkart and Meesho: their sales or settlement reports. Your own sales register also works if it has invoice date, GSTIN, place of supply, taxable value and GST rate columns.
No. Entrifix prepares the GSTR-1 JSON in the format the GST portal's offline tool accepts. You review the summaries, download the JSON, and upload it through the portal or your existing filing workflow.
Yes. Refund and return rows reduce the taxable value, and cancelled orders with zero value are skipped so they do not distort your summaries.