December 2026 due-date chase list for CA firms: every client deadline from 7 to 31 December on one sheet
Short answer (checked 20 Oct 2026): December 2026 has eleven client deadlines on nine dates that a typical CA firm has to chase. Two of those dates fall on a Sunday and one on Christmas Day. The ones you can rely on: TDS/TCS for November deposited by Mon 7 Dec (rule 218, Income-tax Rules, 2026), GSTR-1 by Fri 11 Dec and GSTR-3B by Sun 20 Dec for monthly filers (GST portal), the third advance tax instalment (at least 75% cumulative) by Tue 15 Dec (e-filing portal FAQ), Form 141 challan-cum-statements for November deductions by Wed 30 Dec (rule 218(3)), and on Thu 31 Dec both the FY 2025-26 GST annual return (GSTR-9 FAQ) and the last date for a belated AY 2026-27 income-tax return (Income Tax Department, periods of limitation). This is a starting point, not tax advice. Confirm each date on the portal before you file.
What you get from this guide: a finished December 2026 chase plan for your whole client list. It has one table of every date with its rule and the working day to aim for, a week-by-week plan (23 Nov to 31 Dec) that puts each client request in the week before the date it feeds, a one-row-per-client sheet with one column per December deadline so a filter shows who is still open, a collect list, and five short client scripts. Copy them into your own sheet. Nothing here needs software.
Every December 2026 date, with the day to aim for
| Date (day) | What | Who | Rule / source | Aim to finish by |
|---|---|---|---|---|
| 7 Dec (Mon) | Deposit TDS/TCS deducted or collected in November 2026 | Every deductor/collector (non-government); the challan-cum-statement cases in the 30 Dec row have 30 days instead | Rule 218(2)(b), Income-tax Rules, 2026 (same timelines as old rule 30, per the e-filing FAQ) | Fri 4 Dec |
| 10 Dec (Thu) | GSTR-7 (GST TDS) and GSTR-8 (e-commerce TCS) for November | Government departments and other GST deductors; e-commerce operators | GST Council returns flyer (GSTR-7, 10th); GST portal GSTR-8 FAQ (10th) | Wed 9 Dec |
| 11 Dec (Fri) | GSTR-1 for November | Monthly GST filers | GST portal, GSTR-1 FAQ (11th of the next month) | Wed 9 Dec |
| 13 Dec (Sun) | IFF for November (optional) and GSTR-6 | QRMP filers who want B2B buyers to see November invoices; input service distributors | GST portal IFF FAQ (13th, for the first two months of the quarter); GST Council returns flyer (GSTR-6, 13th) | Fri 11 Dec |
| 15 Dec (Tue) | Third advance tax instalment, tax year 2026-27 (at least 75% of the year's advance tax, cumulative) | Business, profession and capital-gains clients whose tax after TDS/TCS is ₹10,000 or more; presumptive-scheme clients normally pay once, by 15 March | e-filing portal tax-payments FAQ (Income-tax Act, 2025: no policy change to advance tax; ₹10,000 threshold); 15/45/75/100% schedule as in the Income Tax Department limitation table. Check the official source for the new section numbers | Fri 11 Dec |
| 15 Dec (Tue) | PF and ESI contributions for November wages | Employer clients covered by EPF and ESI | Paid within 15 days of the close of the month; payroll rules have been changing in 2026, so check the official source (epfindia.gov.in, esic.gov.in) | Fri 11 Dec |
| 20 Dec (Sun) | GSTR-3B for November | Monthly GST filers | GST portal GSTR-3B FAQ (20th of the next month for monthly filers); CGST Rules, rule 61 | Fri 18 Dec |
| 25 Dec (Fri) | PMT-06 tax payment for November | QRMP filers (second month of the October–December quarter) | CGST Rules, rule 61 (25th of the next month). 25 Dec is Christmas Day, a bank holiday | Wed 23 Dec |
| 30 Dec (Wed) | Form 141 challan-cum-statement for tax deducted in November | Clients who deducted TDS on rent paid by individuals, on property purchase, on contract or professional fees paid by individuals/HUFs, or on virtual digital assets | Rule 218(3), Income-tax Rules, 2026 (within 30 days from the end of the month of deduction) | Mon 28 Dec |
| 31 Dec (Thu) | GSTR-9 annual return for FY 2025-26, and GSTR-9C where it applies | GST-registered clients (GSTR-9 is optional up to the turnover limit notified for small taxpayers; see the GSTR-9/9C chase list and check the official source) | GST portal GSTR-9 FAQ (31 December of the next financial year, unless extended) | Mon 28 Dec |
| 31 Dec (Thu) | Belated income-tax return for AY 2026-27; also your safe date for revised returns | Clients who missed their original due date; clients who need to correct a filed return | Income Tax Department, periods of limitation AY 2026-27: s.139(4) and s.139(5), three months before the end of the assessment year. The Finance Act 2026 change to s.139(5) (later revision with a fee) is covered in the revised ITR guide; check the official source | Tue 29 Dec |
About the Sunday and holiday dates: 13 and 20 December fall on a Sunday and 25 December is Christmas Day. Do not plan on a date moving because of the weekend or the holiday. Aim for the working day before, as in the last column, and treat any later relief as a bonus.
The 31 December pile-up, in one line for clients: the FY 2025-26 GST annual return and the last belated AY 2026-27 return share one date, in the same week as the year-end holidays. Split them: annual returns first (they depend on books and GSTR-1/3B data already filed), belated and revised income-tax returns next, both done by Tue 29 Dec. Any FY 2025-26 credit or correction work had to be done by 30 November (see the November chase list), so GSTR-9 in December should report, not fix.
The easy mistake this month: sending every advance-tax client the same 15 December reminder. Presumptive-scheme clients normally pay once, by 15 March, and clients whose tax after TDS/TCS is under ₹10,000 do not pay advance tax at all. Sort them out first, using the advance tax reminder plan. And if a company client held its AGM after 30 September (for example under an extension), count AOC-4 (30 days) and MGT-7 (60 days) from that actual AGM date; see the ROC chase list.
Week-by-week chase plan (23 Nov–31 Dec 2026)
| Week | Who | What to ask for or do | Tone tip |
|---|---|---|---|
| Mon 23–Sat 28 Nov | Every client | Send one December message per client with only the dates that apply to them (filter your sheet). Ask advance-tax clients for April–November figures and GST clients over the annual-return limit for their FY 2025-26 books, so the year-end work does not all land in the holiday week. | "Before the year-end holidays" gets faster replies than "before the 31st" |
| Mon 30 Nov–Fri 4 Dec | TDS clients; advance-tax clients | Pay November TDS/TCS by Fri 4 Dec. Send each advance-tax client your 15 December estimate with how it was worked out. Start GSTR-9 drafts from filed GSTR-1/3B data. | Send one list of gaps, not item by item |
| Mon 7–Fri 11 Dec | GST deductors; monthly GST; QRMP clients with B2B buyers; ISDs; advance tax; employers | GSTR-7/8 by 9 Dec, GSTR-1 by 9 Dec, IFF and GSTR-6 by Fri 11 Dec. Advance tax paid and challans logged by Fri 11 Dec. PF/ESI for November wages confirmed by Fri 11 Dec. | Ask for nil confirmations in writing |
| Mon 14–Fri 18 Dec | Monthly GST; annual-return clients | Log any advance tax paid on 14–15 Dec. File GSTR-3B by Fri 18 Dec (the 20th is a Sunday). Share GSTR-9 drafts for client review; list differences between books and returns. | "Please check these three numbers" beats a 20-page draft |
| Mon 21–Thu 24 Dec | QRMP clients; annual-return clients | PMT-06 by Wed 23 Dec (25 Dec is Christmas). Get written "OK to file" on GSTR-9/9C. Ask clients with a missed or wrong AY 2026-27 return for documents now. | One "please sign today" message with the time slot |
| Mon 28–Thu 31 Dec | Form 141 clients; GSTR-9; belated/revised ITR | Form 141 for November deductions and GSTR-9/9C by Mon 28 Dec. Belated and revised ITRs filed and e-verified by Tue 29 Dec. 30–31 Dec is buffer: for every client still open, note the acknowledgement or the written reason, and tell the client in writing what is now late. | Never file on presumed consent |
The one-row-per-client sheet
| Client and PAN / GSTIN | Applies (TDS / GST monthly / QRMP / ISD / GST TDS-TCS / advance tax / PF-ESI / Form 141 / GSTR-9 / ITR) | Nov TDS paid (challan, date) | GSTR-7/8 (ARN) | GSTR-1 or IFF (ARN) | Advance tax 15 Dec (challan, ₹) | PF / ESI paid (date) | GSTR-3B or PMT-06 (ARN) | Form 141 (ack) | GSTR-9 / 9C (ARN) | Belated / revised ITR (ack, date) | Owner |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Client A (example, not real) | TDS, GST monthly, advance tax, GSTR-9 | challan no., 4 Dec | n/a | ARN, 9 Dec | challan no., ₹ amount, 11 Dec | n/a | ARN, 18 Dec | n/a | ARN, 28 Dec | n/a | staff name |
| Client B (example, not real) | QRMP, Form 141, ITR | n/a | n/a | IFF ARN, 11 Dec | n/a | n/a | PMT-06 CPIN, 23 Dec | ack no., 28 Dec | n/a | ack no., 29 Dec | staff name |
Put "n/a" in every column that does not apply, so an empty cell always means "still open". A filter on empty cells is your daily status list for the month.
Collect list
- TDS: November payment list with deductee PAN, section and amount; challan details once paid
- Form 141 cases: buyer and seller PAN, property or rent details and payment dates for November deductions
- GST monthly: November sales register, credit and debit notes, e-invoice and e-way bill exceptions
- QRMP: B2B invoices for November (for IFF) and the chosen PMT-06 method (fixed sum or self-assessment)
- Advance tax: April–November profit (or books to 30 Nov), capital gains since April, other income outside the books, TDS/TCS credit so far, and the 15 Jun and 15 Sep challans
- Employers: November wage sheet, joiners and leavers, UAN and IP numbers
- GSTR-9/9C: FY 2025-26 books, filed GSTR-1 and GSTR-3B summaries, HSN-wise summary, and the reconciliation for clients that need GSTR-9C
- Belated or revised ITR: AIS/TIS and Form 26AS, the original acknowledgement (for revisions), the list of changes, and the person who will e-verify
Clients ask fewer "which date is mine?" questions when the dates sit on a one-page calendar with your firm's name on it. Free national dates and a browser .ics builder: free CA due-date calendar tool.
WhatsApp / email script pack
Your December dates: "Hello. Your compliance dates for December: [list only theirs]. The year-end holidays fall in the last week, so please send [items] by [date in the first week]. We will confirm each filing as it is done."
Advance tax: "Based on your April–November figures, we estimate ₹[amount] for the 15 December advance tax instalment. Here is how we got it: [two lines]. Reply YES and we will guide the payment by Friday 11 December."
GST annual return: "Your GST annual return for 2025-26 is due on 31 December. We have prepared a draft from your filed returns. Please check the three figures we have marked and reply 'OK to file' by [date before 24 Dec]."
Property or rent TDS: "Tax you deducted in November on [rent / the property purchase] has to be paid with Form 141 by 30 December. Please send the payment date and the other party's PAN by [date], and we will prepare it for Monday 28 December."
Last call for 2025-26 returns: "31 December is the last date to file a late return for 2025-26, and the safe date to correct one already filed. If you have not filed, or you think something was missed, send us your documents by [date] so we can file by 29 December."
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This guide is general information, not tax advice and not an official government publication. Dates can change by notification or circular. Check the GST portal, the Income-tax e-filing portal, TRACES, the MCA portal, EPFO and ESIC before you file or message clients. Your firm stays responsible for advice to your clients.
Sources to re-check
- Income-tax Rules, 2026, rule 218 (TDS/TCS deposit within seven days from the end of the month; 30 days with Form 141 for rent by individuals, property purchase, contract/professional fees by individuals/HUFs and virtual digital assets): incometaxindia.gov.in
- e-filing portal, tax payments FAQ (rule 218 keeps the old rule 30 timelines; Income-tax Act, 2025 made no policy change to advance tax; ₹10,000 threshold): incometax.gov.in
- Income Tax Department, periods of limitation AY 2026-27 (advance tax 15/45/75/100% schedule; belated and revised returns three months before the end of the assessment year): incometaxindia.gov.in
- GST portal FAQs: GSTR-1 (11th monthly) · GSTR-3B (20th monthly) · IFF (13th) · GSTR-8 (10th) · GSTR-9 (31 December)
- CGST Rules, rule 61 (GSTR-3B 20th; PMT-06 25th): taxinformation.cbic.gov.in · GST Council returns flyer (GSTR-6 13th, GSTR-7 10th): gstcouncil.gov.in
- EPFO and ESIC (monthly contribution dates and any extension): epfindia.gov.in · esic.gov.in
- Related guides: November 2026 chase list · Advance tax by 15 Dec: reminder plan · GSTR-9/9C chase list · Revised ITR last date · AOC-4 and MGT-7 chase list · GSTR-1 chase before the 11th · GSTR-3B chase before the 20th · EPFO ECR monthly date
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