Reviewed by ThaiLawOnline, a licensed Thai law firm practising in Thailand since 2006. Thai lawyer of record: Wichuda Atthamethakon, LL.M., Thai Bar Licence 3149/2556.
Last updated on September 5, 2026
An affidavit (คำให้การเป็นลายลักษณ์อักษร, kham hai kan pen lai lak akson; a court witness statement is a banthuek thoi kham) is a written statement of facts that the maker signs and swears or affirms to be true before a person authorised to take it. Thai law has no single affidavit statute; the document borrows its force from the rules on false statements and from whoever certifies the signature. Foreigners meet affidavits at their embassy before marrying, when a court or pension office abroad wants sworn evidence, and occasionally in Thai civil proceedings.
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Who can take an affidavit in Thailand
Embassies and consulates take affidavits and affirmations from their own nationals, the best known being the affirmation of freedom to marry required by the district office before a foreigner can register a Thai marriage. Some missions, including the United States, United Kingdom and Australian embassies, stopped issuing income affidavits for retirement and marriage extensions in 2019, so those applicants now prove funds with bank documents instead.
Thai lawyers registered for notarial services. Thailand has no notary public system. The Lawyers Council of Thailand registers licensed lawyers who have completed its notarial course to certify signatures, true copies and sworn statements, a role the entry on the notary describes. Their certification is accepted by most foreign banks, courts and immigration authorities, usually after legalisation. Thai courts take sworn evidence in their own proceedings, but do not issue a general purpose affidavit for use abroad. A false statement to an official is an offence under Section 137 of the Criminal Code, and false testimony in court under Section 177.
Practical points: format, legalisation and apostille
An affidavit for use abroad should follow the format the receiving authority expects: title, the deponent’s full name, nationality, passport number and address, numbered paragraphs of fact, a statement that the contents are true, the signature, and the certifier’s attestation with date, place and seal. Attach a copy of the passport page. If it is in English and must be filed in Thailand, a Thai translation is needed.
Legalisation. An affidavit sworn at an embassy in Bangkok and destined for a Thai office is translated into Thai and legalised at the Consular Department of the Ministry of Foreign Affairs. An affidavit certified by a Thai lawyer for use overseas often needs the MFA stamp and then the destination country’s embassy, the chain described in the guide on legalisation of documents in Thailand. That chain is replaced by a single apostille when Thailand’s accession to the Hague Apostille Convention takes effect on 28 February 2027. The common mistake is to swear the affidavit before checking what the recipient will accept.
Affidavit, statutory declaration and witness statement
A statutory declaration is the same document made under a statute that substitutes a solemn declaration for an oath; Commonwealth authorities often ask for it, and the Thai certifier treats it identically. A witness statement in Thai civil litigation is different: a party may file a written statement of a witness in advance in place of the examination in chief, but the witness must still attend for cross examination, and a foreign affidavit on its own carries little weight because the other side cannot question its maker. Where the maker cannot come to Thailand, testimony by video link arranged through the court is the practical solution.
Frequently asked questions
Who can notarise an affidavit in Thailand?
A foreigner’s own embassy or consulate for its nationals, or a Thai licensed lawyer registered with the Lawyers Council of Thailand for notarial services. Thailand has no notaries public. For use abroad the certified affidavit usually needs legalisation at the Ministry of Foreign Affairs and, until 28 February 2027, at the destination country’s embassy.
Is an affidavit sworn in Thailand valid in my home country?
Generally yes, once it is legalised. An affidavit certified by a Thai notarial lawyer is accepted by most foreign courts, banks and authorities after the Ministry of Foreign Affairs and the relevant embassy have authenticated it; from 28 February 2027 a single apostille replaces that chain. Check the recipient’s requirements before swearing it.
Can I use an affidavit as evidence in a Thai court?
Only to a limited extent. Thai civil courts rely on witnesses who attend and can be cross examined. A written statement may be filed in place of the witness’s initial testimony, but the witness must still appear, so an affidavit from someone abroad who will not attend carries little weight; video testimony is the usual alternative.
See also: Notary in Thailand, Affirmation of freedom to marry, Legalization of documents, Apostille, Notary services in Thailand and Legalization of documents in Thailand.
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