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Validation checks

"GSTIN format invalid" - my own, or a buyer's. How do I fix each?

  1. A GSTIN is exactly 15 characters: 2-digit state code + 10-character PAN + entity digit + (usually) Z + checksum. Anything else is rejected by the GST portal on filing, so AprilTax blocks it first.

  2. "Client GSTIN format invalid" - it's YOUR business GSTIN. Open your business (Edit next to the name) and correct it. Copy-pasted? Watch for leading/trailing spaces.

  3. "Recipient GSTIN format" - a BUYER's GSTIN on a B2B invoice. Fix the GSTIN in your source file (B2B sheet or marketplace report) and re-upload.

  4. If the buyer actually has no GSTIN, the sale belongs on the B2C side - move the row to your B2C data instead.

  5. Regenerate and Re-run checks.

More in Validation checks

? What does AprilTax check before I file?
All 30 checks, grouped - HSN, tax arithmetic, documents, e-commerce, reconciliation. › ? A validation check failed - what happens now?
Critical vs advisory findings, and the fix → re-run loop. › ? Why am I asked to set my turnover slab?
The ₹5 Cr slab decides your HSN rules - filing can't proceed without it. › ? A check says my HSN code is "not in the GST master list" - how do I fix it?
The portal rejects unknown HSN codes - correct them in the Review HSN modal. › ? Table 12 doesn't match my sales totals - what do I do?
HSN summary vs Tables 4-11 mismatch - usually fixed by regenerating. › ? A marketplace row shows negative sales or the wrong tax sign - is that a problem?
Negative net supply is usually fine; an opposite-sign tax needs a fix. › ? A check flags "gaps in my invoice series" - should I worry?
Usually cancelled or unused numbers - advisory only, filing isn't blocked. › ? "HSN code must be present on every B2B invoice line" - how do I fix it?
B2B lines always need an HSN of at least 4 digits - fill them in the HSN review table. › ? My turnover is over ₹5 Cr - what extra HSN checks apply?
6-digit codes everywhere, B2C included, and both HSN sections in the JSON. › ? "TCS statement differs from uploaded sales" - what do I do?
The portal's TCS statement and your files disagree - review it in the TCS Match step. › ? "TCS statement operators appear in Table 14" flagged an operator - why?
An operator on your TCS statement is missing from Table 14, or listed under the wrong GSTIN. › ? Other validation flags, decoded - quick reference
The occasional checks: cancellation rate, GST over 40%, duplicate operators, POS mismatch. ›
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