“No SMS came, so I stopped filing”: a simple client deadline reminder system for CA firms
Why reminders beat follow-ups
A reminder before the date costs one message. A missed date costs a late fee, interest and a client who blames the firm. Firms that send a short, predictable reminder every cycle also get documents earlier, which spreads work away from the last two days.
The dates that drive most reminders
| What | Due | Who |
|---|---|---|
| GSTR-1 (monthly) | 11th of next month | Monthly GST filers |
| GSTR-1 (quarterly, QRMP) / IFF | 13th after the quarter / 13th of next month | QRMP filers |
| GSTR-3B (monthly) | 20th of next month | Monthly filers |
| GSTR-3B (quarterly, QRMP) | 22nd or 24th after the quarter, by state | QRMP filers (Telangana and AP: 22nd) |
| TDS/TCS deposit | Within 7 days from the end of the month (March: 30 April; some cases differ) | Deductors |
| Quarterly TDS/TCS statements (Forms 138, 140, 144, 143) | Q2 2026-27: 31 Oct 2026 | Deductors |
The 3-touch rhythm
- 7 days before: "Your GSTR-1 for September is due on 11 Oct. Please send sales invoices by 8 Oct."
- 2 days before: "Two days left for GSTR-1. We still need: purchase register / bank statement."
- On the day (if still pending): "GSTR-1 is due today. Reply 'nil' if there were no sales this month and we will file a nil return."
Keep each message to two lines, name the form and the date, and say exactly what you need from the client. Use the same day and format every month so clients learn the pattern.
What to track per client
- GST frequency (monthly or QRMP) and state (22nd or 24th group)
- TDS deductor? (deposit by the 7th, quarterly statements)
- Preferred channel (WhatsApp, e-mail, SMS) and contact person
- Documents received date per cycle
- Filed date and acknowledgement saved
Common mistakes
- One reminder only, on the due date. Too late to collect documents.
- National dates for every client. Quarterly GSTR-3B depends on the client's state.
- Long newsletters. Clients read two lines with their form name; they skip a page of updates.
- No "nil" option. Make it easy for a client with no transactions to say so, so a nil return goes in on time.
Frequently asked questions
When should a CA firm send GST reminders to clients?
A simple rhythm is three touches: 7 days before the due date (ask for documents), 2 days before (list what is still missing) and on the due date if still pending.
What is the quarterly GSTR-3B due date for Telangana clients?
The 22nd of the month after the quarter, for example 22 October 2026 for July to September 2026.
When are Q2 2026-27 TDS statements due?
31 October 2026 for Forms 138, 140, 144 and the TCS statement in Form 143.
By when must TDS be deposited?
For most deductors, within seven days from the end of the month of deduction under Rule 218 of the Income-tax Rules 2026; for March the date is 30 April, and some payments (such as certain rent or property payments) follow a 30-day rule.
Official sources
- GST portal: GSTR-1 user guide (11th monthly, 13th quarterly)
- GST portal: GSTR-3B user guide (20th monthly, 22nd/24th quarterly)
- GSTN QRMP advisory (state groups)
- Income Tax Department: Rule 218, Income-tax Rules 2026 (TDS deposit dates)
- Income Tax Department: Form 140 FAQs (quarterly statement due dates)
Not tax or legal advice. This is a free explainer of public rules; deadlines and rules can change by notification, so confirm on the official portal or with your CA before you file. Last checked 13 Oct 2026.
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