Auto-Inclusion Scheme Registration: What Singapore SMEs Must Do Before 31 December

If your company had five or more employees at any time during 2026, you are required to be on the IRAS Auto-Inclusion Scheme (AIS), and if you are not on it yet you must register by 31 December 2026 to file employment income for the Year of Assessment 2027. The registration itself is a short online step. The work that takes real time sits behind it: proving your payroll records can produce a correct IR8A for every person you paid this year, and confirming that somebody in your company still holds the Corppass access needed to submit by 1 March 2027.

Does my company actually have to join AIS?

You are required to join if either of these is true: you had five or more employees at any point in the calendar year, or IRAS sent you a Notice to File Employment Income of Employees Electronically. Either one is enough on its own.

The headcount test is wider than most owners expect. It counts full-time and part-time staff, Singapore citizens, permanent residents and foreigners on work passes, company directors who draw any payment, and pensioners. A four-person office that took on two part-timers through a busy quarter has crossed the line, even if the average headcount for the year never reached five.

One detail saves a lot of panic. Registration is a one-time step. If you joined AIS in an earlier year you stay on it and you do not re-register. For those companies 31 December is not the date that matters at all. 1 March is.

What happens if we miss the deadline?

Two separate problems, and only one of them is about penalties.

Miss the 31 December registration and you simply cannot submit through AIS for that year. Every employee then has to declare their own employment income manually, and you have to issue each of them a hardcopy IR8A by 1 March. For a 15-person company that is a day of document preparation plus a month of questions from staff who are not sure which number goes where.

Fail to submit once you are already on AIS and it becomes a compliance matter. Non-compliance with AIS is an offence under the Income Tax Act and IRAS can take enforcement action against the company and its officers, so treat the 1 March date as firm and confirm the current penalty position with IRAS rather than relying on hearsay. In practice the commercial cost lands earlier than any fine: staff whose tax assessments are wrong come to the owner in April, and correcting a submitted IR8A is more work than getting it right once.

Why does IR8A go wrong even when payroll looks correct?

Because IR8A asks for things a monthly payroll run does not naturally separate. Salary and CPF are the easy part and they are rarely where the errors are. The recurring culprits are:

• Benefits the company paid on someone's behalf. Accommodation, a car, club membership, insurance premiums and similar items go on Appendix 8A. These usually sit in accounts payable, not payroll, so nobody in payroll knows they exist.
• Share options or share awards. These need Appendix 8B and are almost always handled outside the payroll system.
• Excess or voluntary CPF contributions. These need IR8S. Common in companies that topped up contributions mid-year without checking the ceiling.
• Director's fees. These are taxable in the year the fee is voted and approved, which is often a different year from the one in which it is paid.
• Allowances treated as reimbursements. A fixed monthly transport allowance is taxable income. Reimbursing an actual documented business expense is not. Many small payroll setups put both in the same line.
• Leavers. Someone who resigned in March still needs a full-year IR8A. If your payroll software archives leavers aggressively, their figures can be hard to retrieve by February.

What should we check in payroll this month?

Five checks, each of which is far cheaper in October than in February.

1. Run the headcount test for 2026 including part-timers, directors and anyone who left. Write down the answer and the date you checked it.
2. Confirm Corppass authorisation for submission of employment income records, and make sure at least two people hold it. A single authorised person who leaves the company in January is the most common reason a filing deadline is missed.
3. Audit employee particulars. NRIC or FIN number, name exactly as it appears on the identity document, date of birth and designation. A wrong identification number is the single most common rejection, and it fails silently until the submission is attempted.
4. Ask directors and managers what the company paid on anyone's behalf during 2026. This is an email, not a system query, and it is the only reliable way to find the Appendix 8A items.
5. Check that your payroll software still supports AIS filing for the current year format. IRAS publishes a list of software that can submit directly. If yours is not on it, you need a different route.

Which submission route suits a 10 to 20 person company?

There are three. Payroll software with seamless filing submits straight from the payroll system with no file handling, which is the lowest-effort option if your software already supports it. The Validation and Submission Application is a free IRAS tool you load a prepared spreadsheet into, and it validates before you submit. The online application in myTax Portal lets you key each employee in by hand.

For most companies under about 30 staff with straightforward salary and CPF only, the free validation tool is enough and costs nothing beyond two to four hours of preparation. Above that headcount, or where benefits in kind recur every year, integrated payroll filing usually pays for itself in the first season because the benefit items are captured as they happen rather than reconstructed in February.

What does this actually buy us?

Correct AIS filing removes employment income from your employees' tax filing entirely. They do not declare it and they do not query it. For the company, the gain is a predictable February instead of a scramble, and a payroll record that can answer a question about any employee in any year without somebody opening a shoebox. The clean-up work listed above is the same work you would otherwise do under deadline pressure, with the cost of errors attached.

FAQ

We only have four employees. Do we still need to register?
Not on the headcount test alone, but check whether IRAS has sent you a Notice to File Employment Income of Employees Electronically. If it has, you are required to join regardless of size. Voluntary registration is also allowed and is worth considering, because it removes employment income from your staff's own tax filing.

We registered for AIS years ago. Is there anything to do before 31 December?
No registration step, because AIS membership carries forward. Your date is 1 March. Use the remaining weeks of 2026 for the Corppass check and the benefits-in-kind email, since both depend on people who are harder to reach in January.

Who should hold the Corppass role for AIS submission in a small company?
At least two people, and ideally not two people who would be away at the same time. One should be a director or the owner. If an external bookkeeper submits on your behalf, they need to be authorised through Corppass as a third party, and you should confirm that authorisation is still active rather than assuming it rolled over.