Thailand WHT Certificate 2026: Section 50 Bis SME Roadmap
Updated: 15 hours ago
For foreign SMEs in Thailand, withholding tax compliance does not end when the return is filed and the tax is paid. A separate document trail still matters: the withholding tax certificate. In practice, this is where many businesses make avoidable mistakes, especially with payroll exits, vendor payments, and cross-border remittances. The Revenue Department’s English text of Section 50 Bis is the core legal starting point.
This guide explains Thailand withholding tax certificate 2026 in plain English: who must issue it, when it must be issued, how the timing differs for employee income versus other categories, what the Revenue Department currently shows about standard certificate forms, and what extra documents are usually needed when a non-resident asks for a certificate for foreign tax use.
Jurisdiction: Thailand.
Last reviewed: aligned with Thai law and practice as at 22 April 2026.
Thailand withholding tax certificate 2026 and the core Section 50 Bis rule
The Revenue Department’s English text of Section 50 Bis states that the person liable to withhold tax must issue a withholding tax certificate in duplicate, with both copies having the same contents. It then sets different timing rules depending on the underlying withholding situation.
For Thailand withholding tax certificate 2026, the three key timing rules published by the Revenue Department are:
for Section 3 Tredecim cases, the certificate must be issued immediately every time tax is withheld
for Section 50(1) cases, the certificate must be issued within the 15th day of February in the year following the tax year, or within one month from the date of termination of employment during the tax year
for Section 50(2), (3), or (4) cases, the certificate must be issued immediately every time tax is withheld.
The same Section 50 Bis text also states that the certificate must be in the form prescribed by the Director-General, and that the Director-General has power to exempt issuance where deemed appropriate.
Different timing for employees versus vendors
Thailand withholding tax certificate 2026 should be controlled through two separate workflows.
First, employee income workflow:
annual issuance by 15 February of the following year, or
issuance within one month after termination if employment ends during the tax year.
Second, vendor and other withholding workflow:
immediate issuance each time withholding occurs for the Section 50(2), (3), or (4) cases described by the Revenue Department text.
Non-resident certificate cases: extra supporting documents matter
If the recipient is a non-resident and needs a certificate for use abroad, the Revenue Department’s English “Non-Resident Withholding Tax” page lists supporting documents that typically must be provided when applying for that certificate:
a copy of the filed withholding tax return such as P.N.D.54
a copy of the tax receipt
a copy of the document showing overseas remittance and exchange rates
a copy of the document showing receipt of payment by the non-resident if payment is received in Thailand
a copy of the invoice
other relevant documents such as a contract.
Key takeaways
Thailand withholding tax certificate 2026 is governed first by Section 50 Bis. The Revenue Department’s English text requires the withholding agent to issue the certificate in duplicate and sets different timing for employee income versus other withholding categories.
For payroll-type withholding under Section 50(1), the certificate is generally due by 15 February of the following year, or within one month after termination during the tax year. For Section 50(2), (3), or (4) cases, issuance is immediate each time tax is withheld.
The Revenue Department still lists the withholding tax certificate in its current English withholding tax form menu.
Where the recipient is a non-resident, supporting documents can include the filed P.N.D.54, tax receipt, invoice, remittance document, and contract.
Call to action (GENTLE LAW IBL)
GENTLE LAW IBL can help foreign SMEs in Thailand build a practical withholding tax certificate process that matches Section 50 Bis timing, supports payroll exits and vendor payments correctly, and reduces friction when foreign-use certificates or non-resident support packs are needed. Contact GENTLE LAW IBL at gentlelawibl.com.
