RET291107
Invoice already filed in GSTR-1
What the portal shows
The invoice no. (s) already exist in the GSTR 1
This invoice number is already present in the filed GSTR-1.
What it means
The number already exists in a GSTR-1 that has been filed. Unlike a duplicate within a single upload, this one is already on record with the department, so correcting it means an amendment rather than a delete and re-upload.
Common causes
- The invoice was already reported in an earlier period.
- A correction was attempted by re-uploading rather than amending.
- The numbering series repeated across financial years.
How to fix it
- Check which period already carries this invoice number.
- If a correction is needed, use the amendment table rather than uploading again.
- Ensure the series does not repeat across years.
This one is catchable before you upload
RET291107 is produced by something already present in your invoice data — our Duplicate invoice number detection within a batch 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.