The Thai Employer’s Payroll Calendar: What to File, and When, All Year

Payroll in Thailand is a calendar job — something is due every month, a cluster of annual filings lands at the start of every year, and nearly every deadline has a penalty behind it. This article puts the main deadlines for the whole year on one page, written from the work our team actually does every month. If you run payroll yourself, use it as your checklist.

Every month

Salary payment on the cycle set in the employment contract, with payslips that itemise every earning and deduction.

Withholding tax (PND 1 / ภ.ง.ด.1) — filed with the Revenue Department by the 7th of the following month (around the 15th for e-filing). This is the summary of tax withheld from every employee's salary that month.

Social security contributions — remitted by the 15th of the following month, at 5% per side, on a wage ceiling of 17,500 baht — a maximum of 875 baht per side per month.

Employee registrations — new employees registered with the Social Security Office within 30 days of their start date; leavers deregistered by the 15th of the following month.

Provident fund (if your company has one) — employee and employer contributions remitted per the fund's rules, typically within a few working days of payday.

January — the heaviest month of the year

Annual workmen's compensation fund contribution — paid by 31 January, calculated on estimated annual wages.

Annual employment conditions report — employers with 10 or more employees file within January.

February — the month of year-end documents

Withholding tax certificates (50 Tawi) — issued to every employee by 15 February. This is the document employees need for their own tax filing, and the one they chase HR for most. Having it ready before anyone asks is the easiest professionalism win of the year.

Annual withholding summary (PND 1 Kor / ภ.ง.ด.1ก) — filed with the Revenue Department by the end of February, summarising every employee's income and tax for the past year. The figures must reconcile with all twelve monthly PND 1 filings — this is where errors accumulated during the year surface.

Actual wage report (Kor Tor 20 Kor / กท.20 ก) — filed with the Social Security Office by the end of February, reconciling actual wages against the estimated workmen's compensation contribution paid in January, with any difference settled or refunded.

March–April — the employee's side (but HR gets the questions)

Personal income tax filing (PND 90/91) is each employee's own duty, due around the end of March (early April online). The company does not file it — but this is when HR is asked about 50 Tawi certificates and year-to-date deductions more than at any other time. A payroll team that has this information ready sails through these two months.

Through the year — things that change and must be tracked

• Minimum wage — adjusted by announcement, and different by province. Check every new announcement against your workforce.
• The social security wage ceiling — scheduled to step up in coming years under announcements already issued. Your payroll calculation must keep pace with each step.
• Labour law updates — such as revised leave entitlements. Review your work rules against current law at least once a year.

Where mistakes actually happen

From the work we see, errors rarely come from ordinary salary runs. They come from the special cases: mid-month starters and leavers, multiple overtime rates in one payroll, incentives that need separate tax treatment, and monthly filings that were never reconciled against the year-end summary. The smaller the team and the more manual the spreadsheet, the more the risk sits in these cases — not the routine ones.

Use this calendar either way — yourself, or with us

If your team runs payroll in-house, the calendar above is a checklist you can use as it is — you do not need to be our client to use it. But if this calendar is consuming too much of your team's time, or the special cases are starting to feel risky, our Payroll Outsourcing service takes over the whole cycle while your employees remain on your company's payroll. We work on an international-grade system in partnership with BIPO, and communicate through your designated contact as a single channel — so your HR always has an answer ready to pass on to employees.

Tell us your headcount and pay cycle, and we will come back with a clear scope and price — no obligation.

Deadlines in this article reflect the current criteria of the relevant authorities at the time of publication. Always check each authority's annual announcements.