CA Firm Compliance Calendar 2026-27: Every GST, ITR & TDS Due Date
Running a CA practice is, at its core, a deadline business. For FY 2026-27, the recurring ones every firm tracks are GSTR-1 by the 11th, GSTR-3B by the 20th, TDS payment by the 7th, advance tax in four instalments, and the annual returns in December. Miss one and the penalty lands on your client and the blame lands on you. Here is the full calendar, laid out the way a firm actually uses it.
One thing before the tables. These are the statutory due dates. The government does extend them now and then, usually right before a deadline, usually for one or two return types. Treat this as your default schedule, not gospel, and check the GST portal or a CBDT notification before you rely on a date in a dispute. With that said, here is what FY 2026-27 looks like.
Monthly due dates
These repeat every single month. For most firms, the 7th, the 11th, and the 20th are the three dates the whole team plans around.
| Compliance | Who it applies to | Due date |
|---|---|---|
| TDS payment | All deductors | 7th of the next month (for March, it is 30 April) |
| GSTR-7 / GSTR-8 | GST TDS deductors and TCS collectors (e-commerce) | 10th of the next month |
| GSTR-1 (monthly filers) | Regular taxpayers not on QRMP | 11th of the next month |
| IFF (optional) | QRMP taxpayers, first two months of a quarter | 13th of the next month |
| GSTR-6 | Input Service Distributors | 13th of the next month |
| GSTR-3B (monthly filers) | Regular taxpayers not on QRMP | 20th of the next month |
| PMT-06 | QRMP taxpayers, monthly tax payment for first two months | 25th of the next month |
Quarterly due dates
If you have clients on the QRMP scheme, on composition, or any TDS to file (you almost certainly do), the quarter-end dates matter as much as the monthly ones. A point worth flagging: GSTR-3B for QRMP clients is staggered by state. Firms in the southern and western states file by the 22nd, firms in the northern and eastern states by the 24th. If your clients span both groups, that is two different dates you are tracking for the same return.
| Compliance | Period it covers | Due date |
|---|---|---|
| GSTR-1 (QRMP) | Each quarter | 13th of the month after the quarter ends |
| GSTR-3B (QRMP) | Each quarter | 22nd or 24th of the month after the quarter, depending on your state |
| CMP-08 | Composition dealers, each quarter | 18th of the month after the quarter ends |
| TDS return (24Q / 26Q / 27Q) | Q1 / Q2 / Q3 / Q4 | 31 July / 31 Oct / 31 Jan / 31 May |
| TCS return (27EQ) | Q1 / Q2 / Q3 / Q4 | 15 July / 15 Oct / 15 Jan / 15 May |
| Advance tax instalments | FY 2026-27 | 15 Jun (15%), 15 Sep (45%), 15 Dec (75%), 15 Mar (100%) |
The advance tax percentages are cumulative, not per instalment. By 15 September a client should have paid 45% of their estimated annual tax in total, not an extra 45% on top of June's 15%. This trips up juniors every year.
Annual due dates for FY 2026-27
These are the once-a-year filings. FY 2026-27 corresponds to assessment year 2027-28, so the income tax dates below fall in 2027. This is the cluster that causes the most chaos, because everything bunches up between July and December and your team is doing it on top of the regular monthly work.
| Compliance | Who it applies to | Due date |
|---|---|---|
| Form 16 (salary TDS certificate) | Employers | 15 June 2027 |
| GSTR-4 (annual) | Composition dealers | 30 June 2027 |
| ITR (non-audit cases) | Individuals and HUFs not requiring audit | 31 July 2027 |
| Tax audit report (Form 3CA/3CB-3CD) | Taxpayers liable to audit under section 44AB | 30 September 2027 |
| ITR (audit cases) | Companies and taxpayers requiring audit | 31 October 2027 |
| ITR (transfer pricing cases) | Taxpayers with international or specified domestic transactions | 30 November 2027 |
| GSTR-9 (annual return) | Taxpayers with turnover above Rs 2 crore (optional below that) | 31 December 2027 |
| GSTR-9C (reconciliation statement) | Taxpayers with turnover above Rs 5 crore | 31 December 2027 |
The deadlines that quietly cause the most damage
After enough filing seasons, you notice it is rarely the big, obvious deadlines that get missed. Everyone remembers the 20th. What slips is the stuff that hides between the headline dates.
- GSTR-3B for QRMP clients in a different state group. Your team internalises one date (say the 24th) and a client in Gujarat or Karnataka was actually due on the 22nd. Two days late, late fee already running.
- The March TDS payment. Eleven months of the year it is the 7th. In April, the payment for March is due on the 30th. People apply the wrong rule in both directions.
- DSC expiry. Not a filing deadline at all, which is exactly why it gets forgotten. A Digital Signature Certificate quietly expires and suddenly you cannot file anything for that client until it is renewed, often on the morning of a due date.
- A new client's first filing. Someone onboarded a client on the 14th, the task for this month's return never got created, and nobody noticed until the client asked for the acknowledgement.
How firms actually track all of this
A calendar like this one is useful for understanding the year. It is useless as an operational tool, because a static table does not know which of your 300 clients is on QRMP, which is on composition, or which has a DSC expiring in eleven days. That mapping is the actual job, and it is too much to hold in one person's head past about 150 clients.
What works is letting the system hold the calendar and the client list together, so the two combine on their own:
- Tasks that create themselves. Instead of someone copying this calendar into a tracker every month, a tool like Finexo's automated task management creates each client's GSTR-1, GSTR-3B, and TDS tasks on the right dates, factoring in whether they file monthly or under QRMP. A client onboarded on the 14th still gets this month's task.
- Reminders tied to the due date, not to memory. Alerts five days, three days, and one day before each deadline, so nobody is relying on remembering that this particular client sits in the 22nd state group.
- DSC and renewal tracking. Expiry alerts well before the certificate lapses, so it never becomes a due-date-morning emergency.
- One view of what is pending. A partner can see, in one screen, how many of this month's filings are done and who is behind, instead of asking the room and waiting twenty minutes for an answer. That visibility is what team workload tracking is for.
None of this changes the dates in the calendar. It changes whether a date can quietly pass without anyone acting on it, which is where the penalties actually come from.
Conclusion
Print this calendar, pin it up, build your year around the 7th, 11th, and 20th. But the firms that get through a filing season without a single late fee are not the ones with the calendar memorised. They are the ones who stopped depending on memory at all, and let a practice management system match every due date against every client automatically. The calendar tells you when. A system makes sure someone actually does it.
Frequently Asked Questions
What are the most important GST due dates for a CA firm in 2026-27?
For monthly filers, the two dates that anchor the month are GSTR-1 by the 11th and GSTR-3B by the 20th of the following month. For QRMP clients, GSTR-1 is due on the 13th after the quarter and GSTR-3B on the 22nd or 24th depending on the state. The annual returns, GSTR-9 and GSTR-9C, are due on 31 December 2027 for FY 2026-27.
When is the TDS payment and TDS return due date?
TDS deducted in any month must be deposited by the 7th of the next month, with one exception: TDS deducted in March is due by 30 April. Quarterly TDS returns are due on 31 July (Q1), 31 October (Q2), 31 January (Q3), and 31 May (Q4).
Why do QRMP clients have two different GSTR-3B due dates?
The GSTR-3B due date for QRMP taxpayers is staggered by state to spread the load on the GST portal. Taxpayers in the southern and western states file by the 22nd of the month after the quarter, while those in the northern and eastern states file by the 24th. If your firm handles clients across both groups, you are effectively tracking two deadlines for the same return.
Are the advance tax percentages cumulative or per instalment?
They are cumulative. By 15 June a client should have paid 15% of estimated annual tax, by 15 September 45% in total, by 15 December 75%, and by 15 March 100%. Each instalment tops up to the cumulative figure rather than adding a fresh percentage, which is a common source of calculation errors.
What happens if I miss a GST filing deadline?
GSTR-1 and GSTR-3B attract a late fee per day of delay (capped, and lower for nil returns), plus interest at 18% per annum on any tax paid late. The bigger cost is often indirect: a delayed GSTR-1 blocks the recipient's input tax credit, which damages the client relationship. This is why firms invest in automated reminders rather than relying on manual tracking.
How can a CA firm track all these due dates without missing any?
A static calendar tells you the dates but cannot map them to individual clients. Practice management software does both: it creates filing tasks automatically for each client based on their filing frequency and registration type, sends reminders before each due date, and shows the partner a single live view of what is pending. This is far more reliable than an Excel tracker once a firm crosses about 150 clients.
Do these dates change every year?
The recurring statutory dates (the 7th, 11th, 20th, and so on) stay the same year to year. What changes are one-off government extensions, which are usually announced close to a deadline for specific return types. Always confirm against the GST portal or a CBDT notification before relying on a date in a contested matter.