PND1 is the monthly withholding tax form submitted by employers to the Revenue Department, reporting the personal income tax withheld from each employee's salary during the month. Any company paying salaries to employees in Thailand — Thai or foreign — must file PND1 every month, even in months where the withholding amount is zero. The annual version, PND1 Kor, reconciles all monthly filings and is due by the end of February each year.

PND91 is the annual personal income tax return for individuals who earn employment income only (as opposed to PND90, which covers other income types). Strictly speaking, it is the employee's responsibility to file their own PND91 by 31 March each year. In practice, many employers in Thailand — particularly those with foreign staff who are unfamiliar with Thai tax procedures — handle this as part of their HR function. We offer PND91 preparation and filing as an annual add-on service.

Yes. Any company hiring its first employee in Thailand must register as an employer with the Social Security Office within 30 days of that hire, and enroll the employee within 30 days of their start date. If you have not yet registered, our one-time setup fee covers both the employer registration and employee enrollment. If you are already registered, we can take over your existing SSO account directly.

Late SSO contributions attract a surcharge of 2% per month on the overdue amount. Late PND1 filings attract a 1.5% per month surcharge on unpaid tax, plus a fine of THB 100 per form filed late. These accumulate quickly for businesses with multiple employees. We process all filings ahead of their respective deadlines as a matter of course — you will not receive a late penalty while your account is active with us.

Yes — we regularly process payroll for mixed teams. Foreign employees working in Thailand are subject to Thai personal income tax on their Thailand-sourced income and are enrolled with the SSO in the same way as Thai employees. There are differences in available tax allowances and deductions for foreign nationals, and some employees may benefit from double tax treaty provisions, which we account for in the monthly withholding calculation. Foreign employees who do not yet have a Thai personal TIN can have this registered as a separate service.

Each month we need: any changes to employee salaries or positions, overtime hours worked, approved leave taken during the pay period, any bonuses or one-time payments, and details of new starters or leavers. Clients using the time attendance add-on submit this data through the system automatically. Others send a simple monthly summary by email. Our team sends a reminder and checklist before each month's cut-off date.

KT20 is the annual Workmen's Compensation Fund declaration filed with the Social Security Office each January. Every company that has SSO-registered employees must file it — regardless of company size or industry. It declares total wages paid during the prior year, which the SSO uses to calculate the employer's annual fund contribution. We handle KT20 preparation and filing as an annual add-on for THB 3,000 per company.