GST Return Filing Matrix 2026: Who Files What and When (GSTR-1, 3B, CMP-08, 4, 9, 9C)
A 2026 reference for every GST return — GSTR-1, GSTR-3B, CMP-08, GSTR-4, GSTR-9, GSTR-9C and the rest. Who files each form, frequency, due dates from primary sources, QRMP Cat A vs Cat B states, and the FY 2024-25 changes that materially shifted the calendar.
Vikram Mehta
@ca_vikram
Vikram is a founding editorial team member at TaxSocial covering the GST and indirect-tax beat. His articles unpack GST 2.0, the new slab structure effective September 2025, the post-sale discount reset, the intermediary-services Section 13(8)(b) amendment, the 30-day IRN reporting rule, the GSTR-1A / GSTR-2B / GSTR-3B filing matrix, and the late-fee mechanics that follow when any of these slip. He writes from the perspective of a practitioner running compliance for mid-sized businesses — what the rule actually says, what the GSTN portal will accept on a given date, and what the practical workaround is when the two diverge. He covers MCA filing and ROC compliance topics where they intersect with GST.
