Fix GST Invoice Mismatches Between Marketplace and Books

Why invoice numbers differ between marketplace and books

Before correcting anything, find out which number is actually wrong. Often neither is. The two systems may be showing different documents or different formats of the same document.

• Different documents: the marketplace report may carry its own invoice or order reference, while your books carry your tax invoice number. Who issues the invoice depends on your arrangement, so check your seller agreement.
• Format changes: prefixes, slashes, hyphens and leading zeros get trimmed in exports, and Excel can turn long numbers into scientific notation.
• Series gaps: cancelled or undelivered orders can leave gaps or reused numbers.
• Returns: credit notes may be booked under a different number or in a different month.
• Timing and manual entry: an invoice raised in one month may be settled in another, and manual entry creates duplicates.

Gather four documents for the same period

Reconcile like with like. Pull all four for the same month and the same GSTIN. If you sell from warehouses in several states, repeat this for each registration.

1. The marketplace sales or order report showing invoice number, order ID and sub-order ID.
2. The marketplace settlement report.
3. Your sales register from your accounting software or ERP.
4. Your filed GSTR-1 data, downloaded from the GST portal.

Save the original exports untouched and work on copies. Format the invoice number column as text before pasting data, otherwise Excel may silently alter the values.

Match on order ID first, then classify each difference

Invoice numbers are the field in dispute, so do not use them as your matching key. Use the order or sub-order ID, which should appear in both the marketplace report and your register. Then sort every unmatched or differing row into one bucket:

• Format only: same invoice, different punctuation or zeros. Normalise and move on.
• Missing in books: the marketplace shows a sale you have not recorded.
• Missing in report: you have an invoice with no marketplace record, which may be a cancelled or manual order.
• Duplicate: one order booked twice.
• Value difference: the invoice number matches but the taxable value or tax amount does not.
• Return-related: a credit note or reversal is missing or numbered differently.

Fix each mismatch in the right place

The correction depends on whether the error sits in your books, in a return already filed, or on the marketplace side.

• Books only: if nothing has been filed yet, correct the entry and record the reason.
• Already reported in GSTR-1: the fix may be an amendment or a credit or debit note. Time limits and conditions apply, so confirm the current GST rules with your tax adviser before filing.
• Marketplace-side error: raise a ticket with the order ID, invoice copy and the exact difference. Keep the ticket reference in your mapping sheet.

Do not delete or silently renumber an invoice that has already been issued. Invoice numbers must follow the format and uniqueness requirements in the GST invoice rules, so check the latest provisions or ask your adviser.

Treat returns, cancellations and credit notes separately

Returns cause a large share of mismatches because one sale can create several documents over several weeks. Keep a separate sheet for them.

• Link each credit note to the original invoice and order ID.
• Check that the return date, not just the sale date, decides the period in which you record it.
• Check whether a cancelled order ever had an invoice generated.
• Compare the refund or deduction in the settlement report with the credit note value.

Unmatched returns are also where recoverable money hides, such as a return deducted from your payout that never reached your warehouse.

Stop the mismatch coming back next month

Run the match before you file, not after a notice or an audit query. Fix the process, not only the entries.

• Keep one mapping table linking order ID, marketplace reference, your invoice number and credit note number.
• Use a fixed numbering series for each GSTIN and document type.
• Always import invoice numbers as text.
• Assign one owner and a monthly cut-off date for reconciliation.

If this takes your team days every month, a tool can help. MarketplaceMetrics by Fundle reconciles marketplace sales and settlements, checks fees against agreed terms and tracks returns and recovery cases. Myntra Excel reports are reviewed, and other marketplaces are in scope discussion.