Compliance calendar
The GST return filing calendar every CA firm tracks
A CA practice doesn't miss the big audit — it misses one of the hundred small GST filings that come due every month. Knowing the calendar cold, and tracking it per client, is what keeps a firm off the notice list.
Here is the core GST filing rhythm as it stands, for both monthly and QRMP filers, plus the annual returns. Individual due dates can be extended by CBIC notification, so confirm the current date for a specific return before you rely on it.
Monthly filers
For taxpayers filing monthly, two returns anchor each month. GSTR-1, the statement of outward supplies, is due by the 11th of the following month. GSTR-3B, the summary return with the tax payment, is due by the 20th of the following month.
So for a given month's supplies, GSTR-1 goes out around the 11th and GSTR-3B around the 20th of the next month — a rhythm that repeats twelve times a year, per client.
QRMP scheme (quarterly returns, monthly tax)
Smaller taxpayers (turnover up to ₹5 crore) can opt for the Quarterly Return, Monthly Payment (QRMP) scheme. Here GSTR-1 is filed quarterly, due by the 13th of the month after the quarter, and GSTR-3B is filed quarterly, due by the 22nd of the month after the quarter for one group of states and the 24th for another.
Tax, however, is still paid monthly under QRMP — through form PMT-06, due by the 25th of each month for the first two months of the quarter. So even a 'quarterly' client has a monthly obligation to track.
The annual returns
GSTR-9, the annual return, is due by 31 December following the financial year — so for FY 2025-26, by 31 December 2026. It is mandatory for regular registered taxpayers above the prescribed turnover threshold (₹2 crore).
Taxpayers above ₹5 crore turnover must also file GSTR-9C, a reconciliation statement between the annual return and the audited financials. This is the reconciliation work that lands on a CA firm's desk at year-end.
Managing it across a book of clients
One client's calendar is memorable; fifty clients' calendars are not. The practical answer is to set each recurring return up once as a series — monthly or quarterly, with its due rule — so every period's filing surfaces on a single calendar before it's late, per client and per entity, rather than living in someone's head or a spreadsheet tab.