Quick answer: IRAS AIS Category A means your payroll software submits employee income data directly to IRAS via API — no manual upload. Category B means you manually upload an IR8A data file to IRAS myTax Portal. Category A requires IRAS-listed software; Category B is available to all employers. AIS is mandatory for employers with 5 or more employees since YA2022.
If you run payroll in Singapore, the Auto-Inclusion Scheme (AIS) for employment income is not optional. Since YA2022, all employers with 5 or more employees must participate in AIS — meaning you must submit your employees' income data to IRAS electronically so it auto-includes in their tax returns. But within AIS, there are two submission methods: Category A (direct API) and Category B (manual file upload). Understanding the difference matters because it affects your software choice, your workflow, and your error risk. This guide explains both categories, who must file, deadlines, penalties, and how to choose. All figures are verified against IRAS as of June 2026. For the broader IRAS filing picture, see our IRAS AIS software guide.
What is the IRAS Auto-Inclusion Scheme (AIS)?
The AIS requires employers to submit their employees' employment income data to IRAS electronically. IRAS then auto-includes this data in the employees' income tax assessments — employees do not need to manually report their employment income.
AIS replaced the old paper-based IR8A form submission. It is mandatory for:
- All employers with 5 or more employees (since YA2022)
- All employers who were already in AIS (enrollment is permanent — you cannot opt out)
The 5-employee count includes all employees on your payroll as of 1 January of the tax year, regardless of employment type (full-time, part-time, casual, foreign employees on work passes).
IRAS AIS Category A vs Category B: the core difference
| Feature | Category A | Category B |
|---|---|---|
| Submission method | Direct API from payroll software to IRAS | Manual file upload to IRAS myTax Portal |
| Software requirement | Must use IRAS-listed AIS software | Any payroll software that generates the file |
| Manual steps | None — fully automated | Generate file, log in, upload, verify |
| Error visibility | Real-time validation feedback | Post-upload validation |
| Best for | Employers wanting automation | Employers with non-listed software |
| Enrollment | Software vendor handles registration | Employer handles file upload |
Source: IRAS, verified June 2026
Category A: Direct API submission
Category A means your payroll software submits employment income data directly to IRAS via an API (Application Programming Interface). The software vendor has integrated with IRAS's system and handles the technical submission.
The process:
- Run your year-end payroll in your software
- The software generates the IR8A data (and Appendix 8A/8B/8E if applicable)
- The software submits the data directly to IRAS via API
- IRAS validates and returns a submission status
- You receive confirmation — no portal login or file upload required
Category A eliminates the manual file generation, download, login, and upload steps. The entire submission happens inside your payroll software.
Category B: Manual file upload
Category B means you generate an IR8A data file from your payroll software and manually upload it to IRAS myTax Portal.
The process:
- Run your year-end payroll in your software
- Generate the IR8A data file (in IRAS-specified format)
- Log in to IRAS myTax Portal via Singpass/CorpPass
- Navigate to the AIS submission page
- Upload the file
- IRAS validates the file and returns errors (if any)
- Fix errors, regenerate, and re-upload
Category B requires manual steps but works with any payroll software that can generate the IR8A file — including software that is not on IRAS's AIS-listed vendor list.
Who must file under AIS?
AIS is mandatory for employers with 5 or more employees as of 1 January of the tax year. The count includes:
- Full-time employees
- Part-time employees
- Casual workers
- Foreign employees on EP, S Pass, Work Permit
- Directors (if they receive director's fees)
Employers with fewer than 5 employees may voluntarily join AIS. Once enrolled, participation is permanent — you cannot opt out even if your headcount later drops below 5.
| Employer Size | AIS Requirement |
|---|---|
| 5 or more employees | Mandatory |
| Fewer than 5 employees | Voluntary (but permanent once enrolled) |
| Already enrolled in AIS | Must continue (permanent) |
Source: IRAS, verified June 2026
AIS filing deadline
The AIS submission deadline is 1 March of the assessment year. For YA2027 (income earned in 2026), the deadline is 1 March 2027.
| Action | Deadline |
|---|---|
| AIS submission (Category A or B) | 1 March of the assessment year |
| IR21 tax clearance (separate from AIS) | At least 1 month before employee cessation |
| Employee tax filing | 18 April (e-filing) |
Source: IRAS, verified June 2026
File early. IRAS processes submissions on a first-come basis, and last-minute submissions in late February can face portal slowdowns due to high traffic.
Penalties for non-compliance
| Offence | Penalty |
|---|---|
| Non-submission of AIS | Up to S$5,000 |
| Late submission | Up to S$5,000 |
| Incorrect submission (negligence) | 200% of tax undercharged |
| Incorrect submission (wilful evasion) | 400% of tax undercharged |
| Failure to retain records | Up to S$5,000 |
Source: IRAS, verified June 2026
The most severe penalties are not the fines — they are the 200% and 400% tax undercharged penalties. These apply when the employer submits incorrect income data that results in the employee under-paying tax. The employer can be held liable for the undercharged tax plus the penalty multiplier.
IRAS-listed AIS software (Category A)
To use Category A, your payroll software must be on IRAS's list of AIS-approved software vendors. As of June 2026, IRAS-listed AIS software includes:
- Talenox (AIS-listed since YA2018)
- QuickHR (AIS-listed)
- Payboy (AIS-listed)
- JustLogin (Category A since YA2020)
- Singroll (AIS e-Submission)
- Various other IRAS-listed vendors
Employers using non-listed software must use Category B (manual file upload). If your current payroll software is not AIS-listed, you have two options:
- Switch to an AIS-listed software
- Continue with Category B manual upload
IR8A vs Appendix 8A vs Appendix 8B vs Appendix 8E
AIS submission includes IR8A and potentially appendices depending on the employee's compensation type:
| Form | Purpose | When to use |
|---|---|---|
| IR8A | Employment income for salaried employees | All employees with employment income |
| Appendix 8A | Benefits-in-kind | Employees receiving non-cash benefits (e.g., car, housing) |
| Appendix 8B | Excess/voluntary CPF contribution | Employees with CPF above the statutory rate |
| Appendix 8E | Pension income | Employees receiving pension (rare) |
Most employers only need IR8A. Appendix 8A is common for employees with benefits-in-kind. Appendix 8B applies when the employer makes excess or voluntary CPF contributions above the statutory ceiling.
How to choose between Category A and Category B
Choose Category A if:
- Your payroll software is IRAS-listed
- You want to eliminate manual upload steps
- You want real-time validation feedback
- You have many employees (the manual upload becomes tedious at scale)
- You want to reduce human error risk
Choose Category B if:
- Your payroll software is not IRAS-listed
- You have a small team and the manual upload is manageable
- You are waiting for your software vendor to achieve AIS listing
- You prefer to review the file before submission
Both categories satisfy the AIS requirement. The difference is workflow efficiency, not compliance.
How payroll software handles AIS submission
Payroll software simplifies AIS submission by:
- Generating IR8A data in the correct IRAS format from year-to-date payroll data
- Calculating total income including salary, bonus, AWS, allowances, and benefits-in-kind
- Generating appendices (8A, 8B) automatically when applicable
- Providing Category A API submission for listed software (fully automated)
- Generating Category B files for non-listed software (manual upload)
- Validating data before submission to catch errors
AIMM Payroll generates IR8A data files in the correct IRAS format from year-to-date payroll data, including salary, bonus, AWS, allowances, and benefits-in-kind. AIMM's direct API submission to IRAS (AIS Category A) is in progress — until then, upload the generated file via the IRAS myTax Portal (Category B). AIMM's flat per-company pricing starts at S$0 (free for up to 3 employees). Start free.
Frequently asked questions
What does IRAS AIS Category A mean?
Category A means your payroll software submits employment income data directly to IRAS via API — no manual file upload. The software handles the entire submission process internally. Category A requires an IRAS-listed payroll software vendor. It eliminates the manual steps of generating, downloading, and uploading the IR8A file.
What is the difference between AIS Category A and Category B?
Category A is direct API submission from IRAS-listed payroll software to IRAS — fully automated, no portal login. Category B is manual file upload — you generate the IR8A file from your software, log in to IRAS myTax Portal, and upload it. Both satisfy the AIS requirement. Category A is more efficient; Category B works with any software that generates the file.
Who must participate in AIS?
All employers with 5 or more employees as of 1 January of the tax year must participate in AIS. The count includes full-time, part-time, casual, and foreign employees. Employers with fewer than 5 employees may voluntarily join. Once enrolled, participation is permanent — you cannot opt out even if headcount drops.
What is the AIS submission deadline?
1 March of the assessment year. For YA2026 (income earned in 2025), the deadline is 1 March 2026. File early to avoid last-minute portal traffic. Late or non-submission carries a penalty of up to S$5,000.
What is the penalty for non-submission of AIS?
Up to S$5,000 for non-submission or late submission. More severely, incorrect submission due to negligence carries 200% of tax undercharged, and wilful evasion carries 400% of tax undercharged. The employer can be liable for the undercharged tax plus the penalty.
Do I need to file IR8A and AIS separately?
No. AIS submission replaces the old IR8A paper submission. When you submit via AIS (Category A or B), you are submitting the IR8A data electronically. You do not file a separate paper IR8A. The AIS submission may also include Appendix 8A (benefits-in-kind) and Appendix 8B (excess CPF) if applicable.
Does AIMM Payroll support AIS Category A submission?
Not yet. AIMM generates IR8A data files in the correct IRAS format for Category B manual upload. Direct API submission (Category A) is in progress. Until then, upload the generated file via IRAS myTax Portal. Start free.
Summary
IRAS AIS has two submission paths: Category A (direct API from listed payroll software) and Category B (manual file upload). Both satisfy the mandatory AIS requirement for employers with 5 or more employees. Category A eliminates manual upload steps and provides real-time validation; Category B works with any software that generates the IR8A file. The deadline is 1 March of the assessment year. Non-submission costs up to S$5,000; incorrect submission carries 200% (negligence) or 400% (wilful evasion) of tax undercharged. Choose Category A if your software is listed; choose Category B if it is not or if you prefer manual control. See our IRAS AIS and IR8A filing guide and IR21 tax clearance guide for the broader tax filing picture.
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