Why it happens
- IGST charged where place of supply equals the supplier's state.
- CGST/SGST charged on an inter-state supply.
- Wrong place of supply.
How to fix it
- Check the place of supply first — it decides the tax head.
- Recompute the tax under the correct head (shown in the proposed fix).
This error is reported in: b2b, b2cl, cdnr, cdnur, exp.
Last checked 17 October 2026
Based on public write-ups of this portal error, not on GSTN's own documentation. If the portal's message differs from what's described here, trust the portal and ask your CA.