RET291109
Supplier GSTIN invalid
What the portal shows
The GSTIN of the supplier is invalid
The supplier GSTIN on an invoice failed validation.
What it means
The supplier GSTIN, rather than the recipient’s, is malformed or does not exist. In purchase-side data this usually means a vendor master holds a wrong or outdated GSTIN — including one that has since been cancelled.
Common causes
- A vendor master holds a mistyped GSTIN.
- The vendor’s registration was cancelled or superseded.
- The GSTIN carries whitespace or lowercase characters.
- A supply from an unregistered vendor was recorded with a placeholder GSTIN.
How to fix it
- Validate the flagged supplier GSTINs against the structure and checksum.
- Confirm the registration is still active — a cancelled GSTIN also blocks input tax credit.
- Correct the vendor master so it does not recur.
- Record genuinely unregistered vendors correctly rather than with a placeholder.
This one is catchable before you upload
RET291109 is produced by something already present in your invoice data — our GSTIN format and checksum validation flags it before the file reaches the portal, so you fix it once instead of discovering it on upload day.
Related errors
Reviewed 13 August 2026. GSTN changes error wording and adds codes without notice, and this is general information rather than tax advice — confirm the current position on gst.gov.in or with your CA.