GSTR-3B Filing (Monthly)
Summary return with tax payment. The one that carries the late fee.
GSTR-1 Filing (Monthly)
Outward supply return. Your buyers cannot claim credit until this is filed.
GSTR-9 Annual Return
The yearly consolidation of everything you filed.
GSTR-9C Reconciliation
Reconciliation statement for turnover above the audit threshold.
CMP-08 Composition Return
Quarterly statement for composition dealers.
GSTR-10 Final Return
The last return, filed after cancellation.