Prepare a GST sales-mismatch working paper by reproducing the exact totals compared in the communication, then explaining the difference through identifiable transactions. Keep taxable value and tax separate, preserve amendment history and test whether the same liability was discharged elsewhere. A matching annual turnover total alone rarely explains a month-specific notice.
Identify what the communication compares
Read the form, period and annexure carefully. A DRC-01B liability intimation under rule 88C is different from an ASMT-10 scrutiny notice or a show-cause notice with its own allegations.
Determine whether the comparison uses GSTR-1, GSTR-1A, GSTR-3B, books, e-invoice data or another source. Notification 12/2024 amended relevant rules to account for GSTR-1A, so an extract ignoring that filed correction may not reproduce the current position.
Record the response route and stated date from the actual communication. Do not assume the deadline or available explanation fields are the same across those processes.
Freeze the original comparison
Save the officer’s or portal’s figures unchanged. Download the filed returns and relevant invoice-level details, recording GSTIN, period and extraction date.
Use separate columns for source taxable value, source tax, corresponding book value, corresponding book tax and difference. A ₹1,00,000 turnover difference is not the same as ₹1,00,000 tax unpaid.
If the accounting software has been updated since filing, retain an audit trail showing the changes. Recreating the filed return from current books without that bridge can conceal the reason the mismatch arose.
An illustrative liability bridge
A Vadodara supplier receives a query comparing ₹4,50,000 outward-statement tax with ₹4,05,000 in the specified GSTR-3B liability comparison. The apparent difference is ₹45,000.
| Investigated component | Illustrative tax ₹ | Required support |
|---|---|---|
| Invoice duplicated in outward statement | 18,000 | One underlying supply and duplicate filing rows |
| Earlier-period invoice tax discharged in another identified return | 15,000 | Invoice, original liability and actual debit trail |
| Amount still unexplained | 12,000 | Further transaction review |
| Total difference | 45,000 | Complete reconciliation to the notice |
The table does not establish that ₹33,000 can automatically be excluded. Verify the legal treatment, dates and whether the authority’s calculation already considered either item. Keep the ₹12,000 visibly unresolved until evidence supports a conclusion.
Classify differences precisely
Useful categories include omitted invoices, duplicate rows, amendments, credit notes, advances, place-of-supply errors and incorrect reporting classifications. Each category should identify the actual transactions rather than function as a convenient balancing label.
For timing differences, show both the original supply period and the period where the amount was reported and paid. Reporting later can explain a comparison while still requiring interest or another review.
For credit notes, connect the note to the original supply, reporting period and applicable adjustment conditions. A commercial credit is not automatically a permitted reduction of GST liability.
Preserve invoice identity across amendments
Use the original invoice number, date, customer GSTIN and later amendment references. Distinguish a changed invoice number from a separate new supply.
If the supplier corrected a customer GSTIN, the same supply can appear under different keys in successive extracts. A simple exact-match spreadsheet may therefore show a false omission and a false additional sale.
Create a stable reconciliation identifier and explain the mapping. Do not delete an unmatched row merely because another row has the same amount.
Link tax payment independently
Match the reviewed liability with filed GSTR-3B values and electronic-ledger debits. Identify any DRC-03 payment separately, with its period, cause, tax heads and issue reference.
A bank deposit into the electronic cash ledger does not establish that the questioned tax was discharged. Likewise, tax paid for another GSTIN cannot be subtracted simply because the legal business name is similar.
Keep CGST, SGST, IGST and cess in distinct columns. A total-tax match can hide a wrong-tax-type problem requiring another correction route.
Reconcile the books without rewriting history
Review sales ledgers, returns, cancelled invoices and unbilled-income entries where relevant. Some book revenue differences arise from accounting recognition or non-GST items rather than missing taxable supplies.
Explain those distinctions with source records. An accounting journal describing revenue timing cannot independently determine GST time of supply or return reporting.
If an actual omission or excess reporting is found, have the adviser assess the correct amendment and payment route, including the fact that the matter has already been raised by the authority. Do not assume every old return can simply be reopened.
Make the reply reproduce the bridge
Use the notice’s allegation order. State the compared figures, supported transaction explanations, accepted amounts if any and remaining disputed or unresolved components.
Attach an evidence index leading to the specific filed rows, invoices and payment records. A spreadsheet with thousands of rows needs a summary that explains why each adjustment is relevant.
Have another person reproduce selected amounts from the source files and check formulas, filters and signs. A hidden filter can make the final difference disappear without actually resolving it.
Track what happens after submission
Retain the exact working version filed with the reply and its acknowledgement. Record later corrections, payments and directions as linked developments rather than replacing the original response.
The useful result is an invoice-level explanation of the particular comparison, with tax and payment consequences assessed separately. That lets the business address real errors while avoiding duplicate payment of amounts already properly recognised and discharged.