ASMT-10 SEE RULE 99(1) NOTICE

Yes, he need to pay the demanded GST, mandatory.

ASMT-10 is a scrutiny notice, not a demand. You reply in Form ASMT-11 within 30 days, explaining the discrepancy. For a GSTR-2B vs GSTR-3B ITC mismatch, the standard explanation is that the supplier uploaded their invoice after the GSTR-2B generation date, so the ITC was taken in the next period once it appeared. Attach the purchase invoices and a period-wise reconciliation showing where the ITC eventually appeared in 2B.

For context on how GST 2.0 changed ITC reconciliation rules from April 2026, this [GST 2.0 rate and compliance guide](https://taxgarden.in/blog/gst-2-simplified-rate-structure-slabs-2026-guide) covers the relevant updates.