Certified translation and document certification
Certified translation for Thai government offices and foreign missions, MFA certification and Apostille, NAATI-certified translation for Australia, and specialist legal, financial, technical and medical translation.
Quick answer
"Certified translation" means whatever the receiving office says it means, and that is the first question to settle. Thai government offices generally accept a translation certified by the translator and then certified by the Department of Consular Affairs; foreign missions in Bangkok each publish their own rule; Australian authorities generally require a NAATI-certified translator. Since 22 December 2024 Thai public documents for other Apostille Contracting Parties are certified with an Apostille rather than embassy legalisation.
Certification routes and who accepts what
Route one: translation plus certification by the Department of Consular Affairs at Chaeng Watthana, used for Thai documents going abroad and for foreign documents being filed with Thai offices. The department certifies the translation against the original, so the original's own authentication must already be in order.
Route two: Apostille. For a destination that is a Contracting Party to the HCCH 1961 Convention, the Department of Consular Affairs issues the Apostille as Thailand's competent authority, effective for Thailand from 22 December 2024. Some receiving authorities still want the translation Apostilled as well as the original — ask before submitting.
Route three: embassy legalisation, still required for destinations that are not Contracting Parties. Each mission sets its own translator list, appointment system and stamp sequence.
NAATI-certified translation for Australia
Australian government bodies, including the Department of Home Affairs, generally require documents not in English to be translated by a translator certified by NAATI (the National Accreditation Authority for Translators and Interpreters). The translator's certification number and stamp must appear on the translation.
A NAATI translation is a different product from an MFA-certified Thai translation; ordering the wrong one usually means paying twice, so confirm the destination requirement before work starts.
Legal and financial translation
Contracts, court documents, company affidavits and audited financial statements require terminology consistency across the whole document set. A bilingual glossary agreed at the start prevents the situation where the same defined term appears three ways across three filings.
Where a bilingual contract will be enforced in Thailand, the controlling-language clause matters more than the translation quality: Thai courts work in Thai and will require a Thai version of any foreign-language exhibit.
Technical, medical and localisation work
Technical manuals, regulatory dossiers and clinical documents are handled with translation-memory and terminology control. ISO 17100 sets requirements for translation services including reviser competence, and ISO 18587 covers post-editing of machine translation output — useful reference points when specifying quality expectations.
Language pairs and sworn translators abroad
Some civil-law jurisdictions maintain sworn or court-appointed translator registers, and their consulates accept only translations from those registers. Where the destination requires a sworn translator in its own country, the practical route is to prepare the authenticated Thai original here and have the sworn translation produced at the destination.
Document checklist
- The destination office's written requirement, if you have it — this decides the route
- Clean scans of every page of the original, including reverse sides and stamps
- The exact spelling of names as they appear in the passport
- Any earlier translation used with the same authority, for consistency
- The deadline set by the receiving office, not just your own
- For NAATI work: confirmation that the Australian body requires NAATI certification
Before you engage
- Settle the certification route before translation begins; the route changes the format of the deliverable.
- Give the passport spelling of every name — transliteration mismatches are the top rejection cause.
- Order enough certified sets at once if several authorities will each keep an original.
- Check whether the receiving office requires the Apostille on the original, the translation, or both.
Common pitfalls
- Assuming an Apostille certifies content — it certifies the signature, seal and capacity, nothing more.
- Submitting a translation to an embassy that only accepts its own listed translators.
- Sending a partial scan that omits back-page stamps, which invalidates the certification.
- Using machine output for a legal filing without qualified revision.
Frequently asked questions
What does an Apostille actually certify?
Under the HCCH 1961 Convention an Apostille certifies the authenticity of the signature, the capacity in which the signatory acted, and the identity of the seal or stamp on the document. It does not certify the content of the document or the accuracy of any translation attached to it.
Does Thailand issue Apostilles?
Yes. The Convention entered into force for Thailand on 22 December 2024 and the Department of Consular Affairs, Ministry of Foreign Affairs, is the designated competent authority. Documents destined for non-Contracting States continue to use consular legalisation.
Do I need a NAATI translation for an Australian visa?
Australian authorities generally require documents in a language other than English to be accompanied by a translation from a NAATI-certified translator, with the certification details shown. Check the specific programme's document checklist, because requirements differ between visa, skills assessment and registration bodies.
Can you certify a translation someone else produced?
It has to be reviewed and taken on as our own work before any certification can be given, because the certifying party is attesting to the translation's completeness and accuracy. In practice a full review of a third-party translation is often comparable in effort to retranslation.
How long is a certified translation valid?
Certification does not expire in itself, but many receiving offices impose their own validity window — commonly three or six months from issue for civil status documents. The receiving office's rule governs.
What does a certified translation cost?
This site does not publish prices because language pair, document type, certification route and turnaround all change the arrangement. Send the scans to staff by phone, LINE or email for scoping.
Primary sources
- Department of Consular Affairs, MFA — Document legalisation and Apostille service
- HCCH — 1961 Apostille Convention — text and status table
- NAATI — Certified translator credentials (Australia)
- ISO — ISO 17100 translation services requirements
Reviewed as of 2026-08-04. General guidance only, not case-specific advice and not a guarantee of outcome. Fees, conditions and processing times are set by the responsible authority and can change. This site does not publish prices — please ask our staff.
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