Withholding Tax Certificate (Section 50 bis)
A withholding tax certificate under Section 50 bis of the Revenue Code is issued by the payer of the income. It proves tax was withheld and remitted, and supports foreign tax credit or refund claims abroad.
Section 50 bis of the Revenue Code requires the withholding agent to issue a certificate to the person from whom tax was withheld. It is therefore the payer's document, not the Revenue Department's — which determines whether notarial signature certification is needed before legalisation.
For a foreign tax credit claim, recipients typically want three things visible at once: who the income belonged to, what category of income it was, and how much tax was withheld. Certificates missing any of these are usually returned.
Where the recipient wants proof the tax was actually remitted rather than merely withheld, add the payer's remittance evidence or a Revenue Department certificate of payment of tax.
For payments to recipients abroad, the withholding rate may be reduced under a double taxation agreement, and claiming that generally requires the recipient's own certificate of residence. Plan both documents together.
Documents to prepare
- The Section 50 bis certificate issued and signed by an authorised officer of the payer
- The payer's remittance evidence, such as the withholding return with proof of payment
- Identification of the person from whom tax was withheld, with taxpayer ID
- Contract or invoice showing the income category, where the recipient asks for support
- A certificate of residence, where treaty benefits are being claimed
- The payer's company affidavit, to confirm the signatory's authority
Step order
- Obtain the certificate from the payer and check every field, including the income category, is completed
- Verify the signatory's authority against the payer's company affidavit
- Have the authorised person sign before a Notarial Services Attorney where the recipient requires it
- Have it translated by a translator who signs and takes responsibility
- File for legalisation at the Department of Consular Affairs
- Legalise at the destination embassy or consulate, or obtain an apostille once the Convention is in force
Pre-filing checklist
- Income category, gross amount and tax withheld are all stated
- Names and taxpayer IDs of both payer and payee are correct
- The signatory has authority under the current company affidavit
- Remittance evidence is attached where actual remittance must be proved
- The tax year matches the year of the foreign credit claim
Practical tips
- Collect the certificate each time tax is withheld rather than chasing the payer at year end
- Keep a scan alongside the original so figures can be checked without handling the copy going abroad
- Where the payer is a multinational, confirm the Thai signatory has actual authority, not the parent company
- Plan the certificate of residence in parallel where treaty benefits will be claimed
Common pitfalls
- Assuming the Revenue Department issues it, when Section 50 bis places that duty on the payer
- A signatory without authority under the company affidavit, so notarial certification cannot proceed
- An income category that does not match the facts, leading the recipient to refuse the credit
- Sending an uncertified copy abroad when the recipient requires an original or certified copy
Frequently asked questions
Who must issue a withholding tax certificate?
The payer of the income, as the withholding agent, under Section 50 bis of the Revenue Code — not the Revenue Department.
What is it used for abroad?
As evidence that Thai tax was withheld, supporting a foreign tax credit or refund claim under the destination country's domestic law or an applicable double taxation agreement.
Is notarial certification required?
It depends on the recipient. As a private document, it usually needs an authorised signatory to sign before a Notarial Services Attorney before consular legalisation.
What if the certificate is lost?
Ask the payer to reissue a substitute from its records, and request the remittance evidence so the recipient can verify the figures.
Must remittance evidence be attached?
Not always, but where the recipient must see that the tax reached the state, attaching the withholding return with proof of payment avoids follow-up questions.
How does the chain change under the Apostille Convention?
Once it enters into force for Thailand on 28 February 2027 per HCCH, and where the destination is a party, an apostille replaces the embassy step. Signature, notarial certification and translation are unchanged.
For a document review before you file, contact us on LINE @nycli, call +66-83-249-4999 or email nycli@ilc.ltd. Our team will confirm the steps, any missing documents and a realistic timeline for your case.
Related cases
- Certificate of Residence for Tax Purposes
- Income Tax Returns (PND 90/91 and PND 50)
- VAT Registration Certificate (PP 20) and VAT Documents
- Import and Export Declarations and Customs Documents
- Tax Clearance Certificate and Certificate of Payment of Tax
Official references
Requirements on this page follow the rules published by the authorities below. Always confirm the latest notice on the official site before filing.
- The Revenue Department
- Thai Customs Department
- Department of Consular Affairs, MFA ThailandThailand's authority for document legalization and Apostille
- HCCH — Apostille Section (Hague Convention 1961)Thailand's accession enters into force 28 February 2027
Related services
Fees depend on document type, number of pages and turnaround. Send scans to LINE @nycli, call +66-83-249-4999 or email nycli@ilc.ltd for a written quotation.