Social security in Thailand: when does registration become mandatory?
From the first employee: there is no minimum headcount. The company registers as an employer and registers each employee within 30 days of that person starting work, then withholds 5% of wages, matches it, and files and pays every month by the 15th.
Last reviewed 26 October 2026
The four filings, and when each one is due
| What | Form | Deadline |
|---|---|---|
| Register the company as an employer | สปส.1-01 | Within 30 days of the first employee starting |
| Register each employee | สปส.1-03 | Within 30 days of that person starting |
| Pay contributions, both shares | สปส.1-10 | 15th of the following month, every month |
| Report a leaver | สปส.6-09 | 15th of the month after they leave |
One employee is enough to trigger all of it. Owners who hire a single assistant or a part-time bookkeeper on salary are often surprised by that, because the rest of Thai employment law has thresholds at ten staff that social security does not.
What it costs
The contribution is 5% of the employee’s wage, deducted from their pay, and the company pays a matching 5% on top. Both are calculated on monthly wages up to a ceiling, which went up on 1 January 2026 from 15,000 to 17,500 baht. So the most either side pays is now 875 baht a month per employee, or 1,750 baht combined.
| Period | Wage ceiling | Maximum monthly contribution, each side |
|---|---|---|
| 2026 to 2028 | 17,500 baht | 875 baht |
| 2029 to 2031 | 20,000 baht | 1,000 baht |
| From 2032 | 23,000 baht | 1,150 baht |
Separately, the company pays a small Workmen’s Compensation Fund premium on its own, with no employee share: 0.2% to 1.0% of wages depending on the risk class of the business, assessed once a year and payable by 31 January. Office businesses sit at the bottom of that range.
What happens if you are late
The monthly filing is the same date on the compliance calendar every month, including months where nobody joined or left. Most companies hand it to whoever runs payroll; what payroll outsourcing costs shows the price shapes, and the payroll request form asks whether your employer account already exists, so firms quote for the registration as well if it does not.
Related questions
- Hiring your first employee in Thailand: what is the compliance checklist?
- What does a Thai employee actually cost on top of salary?
- PND 1 or PND 1 Kor: which one, and when?
Sources
- Baker McKenzie: Thailand raises the maximum wage base for social security contributions from January 2026
- KPMG Thailand Tax News Flash 157: 2026 to 2032 wage ceilings and maximum contributions (PDF)
- Social Security Office, form สปส.1-03 with the printed 30 day and penalty warnings (Thai, PDF)
- Social Security Office, สปส.1-10 contribution return with the 2% surcharge (Thai, PDF)
- FlowAccount: the Workmen’s Compensation Fund, rates and the 31 January payment (Thai)
This is general information about how a filing works, not accounting or tax advice for your company. Confirm anything that matters against the official notice or with your accountant. Spotted something out of date? Tell us and we will fix it.