If you sell on Amazon India and file GST returns, you've almost certainly noticed this: the numbers in your Amazon Monthly Transaction Report don't match what you've declared in GSTR-1 or GSTR-3B. Usually not by a large margin — but enough to cause anxiety at return time, and enough to matter if you're ever assessed.

This post explains why the mismatch happens and a practical approach to closing it.

Why the MTR and GST don't naturally align

The MTR is Amazon's financial ledger for your seller account. It records every transaction — sales, returns, fees, reimbursements, adjustments — in Amazon's settlement periods, which run on a roughly two-week cycle.

GST is reported by calendar month and applies at the tax point of a sale, typically when goods are dispatched — not when Amazon settles your payment.

Three mismatches are nearly universal:

1. Settlement period vs. calendar month. A sale on January 31st may settle in Amazon's February cycle. The MTR shows it in February. GST should reflect it in January. If you pull MTR data and use it as your GST source without adjusting for this, you're already off by a month on some transactions.

2. Returns and credit notes. When a customer returns an item, Amazon credits your account. In GST, a return that crosses a month boundary requires a credit note in GSTR-1. The MTR shows net revenue; GST requires gross sales and credit notes as separate line items.

3. Amazon TCS (Tax Collected at Source). Under Section 52 of the GST Act, Amazon deducts 1% TCS on taxable sales and remits it to the government directly. This appears in your MTR as a deduction. It also appears in Form GSTR-8, which Amazon files. You can claim it as input credit in GSTR-3B — but only if you've reconciled the numbers correctly first.

What the reconciliation actually involves

A complete MTR-to-GST reconciliation maps:

  • Gross sales (MTR by dispatch date, not settlement date) → GSTR-1 outward supplies
  • Returns (MTR) → Credit notes in GSTR-1
  • TCS deducted (MTR) → TCS credit claimed in GSTR-3B
  • Amazon fees (MTR) → Expenses in books, with input GST applied where applicable

Each mapping requires filtering and grouping the MTR by dispatch date, then cross-referencing with your invoice records.

Where the manual approach breaks down

Most small sellers do this in Excel. MTR export → filter by date → group by GSTIN → calculate. It works until:

  • You have more than 200–300 orders per month (formula complexity grows fast)
  • You sell across multiple states with different tax rates
  • Your return rate is high (credit note tracking becomes its own project)
  • You're reconciling retroactively for six months for a scrutiny assessment

At that scale, the error rate in manual reconciliation becomes meaningful — and GST penalties for mismatches between GSTR-1 and GSTR-3B are real, not theoretical.

A more reliable approach

The mechanical parts of this process — pulling numbers from the MTR, applying dispatch-date logic, grouping by GSTIN, generating credit notes — are what software handles well. Done right, the output is a GSTR-1-ready file that your CA can review in 20 minutes rather than two hours.

What automation doesn't replace is judgment: HSN code classification, disputed return cases, and split-state supplies all require human review. The goal isn't to remove the accountant from the loop — it's to make sure the accountant is reviewing a structured input rather than building it from scratch every month.

The honest numbers

A manual MTR-to-GST reconciliation for a seller with 300–500 monthly orders typically takes 3–5 hours per month. Structured import with date-logic and credit note handling cuts that to 30–45 minutes. At CA billing rates, that's a real cost difference over a year.

Ready to automate your reconciliation? Try the Alstar ERP →