What the checker looks at
Most GSTR-1 corrections trace back to a handful of data problems in the sales register: a mistyped GSTIN, an invoice number used twice, tax charged under the wrong head, or an invoice dated in a different month. This tool runs those checks on every row and then totals the clean data the way GSTR-1 asks for it.
- Recipient GSTIN: 15-character format, state code and check character (format only, not live registration status).
- Invoice number: up to 16 characters using letters, digits, hyphen and slash; repeated numbers in the period.
- Date: valid date inside the tax period you select.
- Tax head: IGST for inter-state supplies, CGST + SGST for intra-state supplies, based on place of supply versus your state.
- Tax amount: tax ≈ taxable value × rate, within ₹1, and CGST equal to SGST.
- HSN and UQC: present, 4/6/8-digit HSN, and a unit wherever a quantity is given.
Example (illustrative)
A Rajkot tile trader registered in Gujarat (state code 24) loads September’s register. An invoice to a registered buyer in Maharashtra goes to B2B with IGST. A ₹1,77,000 invoice to an unregistered buyer in Rajasthan is inter-state and above the threshold entered, so it is shown as B2CL. A ₹10,500 walk-in sale within Gujarat is B2CS. One row shows CGST ₹180 and SGST ₹175, which the checker flags because the two halves should be equal.
Common mistake
Deciding IGST or CGST + SGST from the buyer’s address instead of the place of supply. For goods, the place of supply usually follows where the movement of goods ends, so enter that state code in the register and check the tax head against it.
Limitations
The checker does not cover credit and debit notes, amendments, exports, SEZ supplies, nil-rated or exempt supplies, advances or documents issued. It does not create the portal JSON. Confirm rates, thresholds and table-wise reporting rules on the GST portal and GST tutorials.