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.
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Thai citizenship by naturalisation (การแปลงสัญชาติ, naturalization in American spelling, also Thai nationality) is the grant of Thai nationality to a foreigner under the Nationality Act B.E. 2508 (1965), at the discretion of the Minister of Interior. It removes every immigration formality: no visa, no extension, no work permit, and the right to own land in one’s own name. It is the last step of a long road, normally after permanent residency, and the Act nowhere obliges a new Thai to give up the nationality they already hold.
Table of Contents
What the Nationality Act requires
Section 10 of the Nationality Act lists the conditions: the applicant has reached majority under both Thai law and the law of their own nationality; is of good behaviour; has a regular occupation; has been domiciled in Thailand for a continuous period of not less than five years; and has knowledge of the Thai language as prescribed by ministerial regulation. In practice the five years are counted as years of permanent residency, so the usual sequence is three years of extensions, a residence permit, five years as a resident, then naturalisation.
Section 11 relaxes the rules for certain applicants, including the husband of a Thai national, for whom the five-year domicile and the language conditions do not apply, and Section 9 allows a foreign woman married to a Thai national to apply for nationality by marriage without naturalisation at all. The Ministry of Interior applies a points assessment out of 100, pass mark 50, scoring age, education, income, residence, language and ties to Thailand. The grant is published in the Royal Gazette and can be refused without reasons.
Applying at Special Branch and what it costs
Applications are lodged with the Special Branch Bureau of the Royal Thai Police, at the National Police headquarters on Rama 1 Road in Bangkok, or with the provincial police for applicants outside Bangkok. The file includes the passport and residence books, work permit and tax returns, the marriage certificate where relevant, a police clearance certificate and photographs. The Act caps the application fee at 10,000 baht and the certificate fee at 1,000 baht, and the amount actually charged is set by ministerial regulation within those caps, so confirm it when you file.
The interview is in Thai. The applicant is expected to speak conversational Thai and to sing the National Anthem and the Royal Anthem; the foreign husband of a Thai national is excused the statutory language requirement by section 11(4), but not the interview, while a foreign wife applies under section 9 instead. Income is the point most applicants fail: a foreigner working in Thailand is expected to earn at least 80,000 baht a month, reduced to 40,000 baht a month for one married to a Thai. The process takes several years from filing to the Gazette notice.
Citizenship compared with permanent residency
| Point | Permanent residency | Thai citizenship |
|---|---|---|
| Land ownership | Not permitted | Permitted, as a Thai national |
| Work permit | Still required | Not required |
| Passport | Foreign passport plus residence books | Thai passport and ID card |
| Loss | Absence over one year without endorsement | Revocation by the Minister under Section 19, including for fraud, continued use of the former nationality, or living abroad without a Thai domicile for over five years |
| Military service | Not liable | A naturalised man must register but is not called for selection in peacetime (Military Service Act section 14(8)) |
A resident remains a foreigner under the Land Code; a naturalised Thai is a Thai for the Land Code and the Foreign Business Act, with one notable difference at conscription: a naturalised man is registered but not called for selection in peacetime (Military Service Act section 14(8)). Thailand tolerates dual nationality in practice; whether the home country does is a separate question to check before applying. Children of a Thai mother or father are Thai from birth and need no naturalisation; the military service rules then apply to sons in full.
Last reviewed: 29 September 2026. Nationality Act B.E. 2508 sections 9, 10 and 11 (as amended to Act No. 5 B.E. 2555) and the fee ceilings, and Military Service Act B.E. 2497 section 14(8), were checked against the Thai texts on file. The points test, the income thresholds and the interview practice are the Ministry of Interior’s administrative criteria as commonly reported and were not re-read in this review.
Frequently asked questions
How long does it take to get Thai citizenship?
Count on a decade or more in total. The usual path is three years of one-year extensions, a permanent residence permit, five years as a resident, and then a naturalisation application that itself takes several years to reach the Minister’s decision and the Royal Gazette. A husband of a Thai national can skip the five-year domicile rule but still waits years for the decision.
Does Thailand allow dual citizenship?
The Nationality Act contains no general rule that a person who naturalises as Thai must give up their existing nationality, and many naturalised Thais keep both passports. However, Section 19(2) allows the Minister to revoke a naturalisation where there is evidence that the person still uses their former nationality. Whether the other country permits its citizens to hold a second nationality is a separate question and should be checked before applying.
Can I get Thai citizenship by marrying a Thai?
Marriage helps but does not by itself confer nationality. A foreign woman married to a Thai national may apply under Section 9 of the Act; a foreign man married to a Thai woman applies for naturalisation under Section 10 with the relaxations in Section 11, which remove the five-year domicile and language conditions but keep the income, conduct and occupation tests.
See also: permanent residency, police clearance certificate, pink ID card, Land Code, and the guides on why to seek Thai citizenship and permanent residency in Thailand.
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