By KYN AI Advisory Team — AI implementation specialists, Singapore
For a Singapore company with a 31 December year end and quarterly GST periods, the 2027 calendar runs as follows: IR8A by 1 March, ECI by 31 March, GST returns on 30 April, 31 July and 31 October, AGM by 30 June, annual return by 31 July, Form C-S by 30 November, and CPF by the 14th of every month. Each date comes from a rule you can check at the agency page linked below. If your year end or GST period differs, the dates move, and the rules in this article show how.
How is this calendar built?
Assumptions, stated so you can adjust:
- Financial year end: 31 December 2026 for the filings in 2027, and 31 December 2027 for the 2027 year end.
- GST: registered, quarterly accounting periods ending 31 March, 30 June, 30 September and 31 December.
- Company type: non-listed Singapore company, no overseas branch register.
- Employer: has employees in Singapore and files through the Auto-Inclusion Scheme.
Fact: each rule below was read at the agency page on 30 October 2026. Judgement: the dates are our calculation from those rules. Weekends and public holidays can change a deadline in practice. Where a date falls on a weekend we say so, and you should check the agency's treatment before relying on a roll-forward.
What is the 2027 calendar by date?
| Date in 2027 | Day | Obligation | Rule | |---|---|---|---| | 14th of each month | varies | CPF contributions for the previous month | Enforcement applies after the 14th of the following month | | 31 January | Sunday | GST return and payment, October to December 2026 period | 1 month after period end | | 1 March | Monday | IR8A for 2026 income | 1 March of the year after the income | | 31 March | Wednesday | ECI for the year ended 31 December 2026 | Within 3 months of year end | | 30 April | Friday | GST return and payment, January to March 2027 | 1 month after period end | | 30 June | Wednesday | AGM for the year ended 31 December 2026 | Within six months of year end | | 31 July | Saturday | Annual return for the year ended 31 December 2026; GST, April to June 2027 | Seven months after year end; 1 month after period end | | 31 October | Sunday | GST return and payment, July to September 2027 | 1 month after period end | | 30 November | Tuesday | Form C-S, C-S (Lite) or Form C for the 2027 year of assessment | Due 30 November each year | | 31 January 2028 | Monday | GST return and payment, October to December 2027 | 1 month after period end |
Days of the week are from the calendar. Three of the dates fall on a weekend: 31 January, 31 July and 31 October. Plan to finish on the working day before.
What are the sources for each rule?
- GST. IRAS states that your GST return and payment are due 1 month after the end of your accounting period/filing-gst/due-dates-and-requests-for-extension). IRAS's examples are 30 April for January to March, 31 July for April to June, 31 October for July to September and 31 January for October to December.
- ECI. Companies file within 3 months from the end of the financial year-filing). A company does not need to file if annual revenue is $5 million or below and ECI is nil for the year of assessment.
- Form C-S, C-S (Lite) and Form C. Due on 30 November each year, per IRAS.
- IR8A. Employers must provide or submit employee income records by 1 March of the year after the income is derived-for-employment-income/reporting-employee-earnings-(ir8a-appendix-8a-appendix-8b)). Employers in the Auto-Inclusion Scheme submit electronically to IRAS. Others give hardcopy forms to employees.
- AGM. Non-listed companies hold the AGM within six months after the financial year end, per ACRA.
- Annual return. For non-listed companies, seven months after the financial year end, and eight months for companies with both share capital and an overseas branch register.
- CPF. Contributions are due on the last day of each month; CPF Board takes enforcement action if payment is not made by the 14th of the following month, and charges interest of 1.5% a month from the day after the due date.
How does the calendar change with a different year end?
Shift the year-end-linked dates by the same number of months.
| Year end | ECI | AGM | Annual return | |---|---|---|---| | 31 March | 30 June | 30 September | 31 October | | 30 June | 30 September | 31 December | 31 January | | 30 September | 31 December | 31 March | 30 April | | 31 December | 31 March | 30 June | 31 July |
Form C-S stays at 30 November each year whatever your year end. GST depends on your accounting period, not your financial year, so check your period in myTax Portal. A company with a 30 June year end and calendar-quarter GST has year-end dates and GST dates in different months, which is where deadlines get missed.
What should the sheet look like?
Build it as a table with one row per obligation and these columns:
- obligation;
- rule and source link;
- due date;
- working-day target, set at least three working days earlier;
- owner;
- backup owner;
- inputs needed (for example, closed books, payroll totals);
- status and date completed.
Add two review rows: a January check of every rule against its source, and a July check. Rules change. In 2026 the CPF Ordinary Wage ceiling reached $8,000 a month, which is why the rule column links to its source, not to a remembered number. We cover other 2026 changes in our half-year review of Singapore SME rules.
What gets missed most often?
From our client reviews, not a survey:
- Dependencies, not dates. ECI needs a closed year. If the close finishes late, the date is missed upstream. See monthly close time.
- One owner, no backup. A filing tied to one person's leave.
- Hong Kong, Indonesia and Malaysia entities. A group with entities in several countries needs one calendar per jurisdiction. This one covers Singapore only.
- Payroll dates against the 14th. Late payroll runs push CPF past the 14th.
Where KYN fits
A compliance calendar is rule-based and date-driven, so it automates well. KYN's own books run bills from Gmail, receivables chased at 3, 14 and 30 days, and payroll on 2026 CPF rules. The same approach produces a deadline register that checks inputs, such as whether the books are closed, and reminds the owner and the backup on WhatsApp.
Filings and payments wait for a named person, and every action is logged with the actor. The first 14 days are a review of your stack and interviews with the team. A full build ships in under 90 days, in a cloud account in your name. See finance and security.
Frequently asked questions
When is the Form C-S deadline in 2027?
IRAS states that Form C-S, C-S (Lite) and Form C are due on 30 November each year. In 2027, 30 November is a Tuesday.
When is the AGM and annual return due for a December year end?
A non-listed company holds its AGM within six months and files its annual return within seven months of year end, per ACRA. For a 31 December year end that is 30 June and 31 July. The annual return gets eight months if the company has both share capital and an overseas branch register.
Does a weekend deadline roll to Monday?
We did not confirm a roll-forward rule for each obligation, so plan to finish on the previous working day. Check the agency page for the treatment of weekends before you rely on a later date.
Checked 30 October 2026.
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