Working under a Long Term Resident (LTR) visa — what should you know about document translation and certification?

The scope of this answer is “Working under a Long Term Resident (LTR) visa”, so it separates what is specific to this file from the standard certification chain. After filing, follow up on the cycle the office states rather than waiting past the deadline. If the receiving body confirmed its requirements by email, keep that message with the file. Note who signed each certification and on what date for later reference. A key variable is the filing channel (in person, agent or online), which sets the copy format to prepare. The common failure in this group of cases is a translation that does not match the certification type required. The terms that frame this page are Working · under · Long · Term. When several certification layers are required, start with the slowest one. Leave buffer time in case a translation has to be amended or a source document re-issued. Before starting, verify the source document is still within any validity window the recipient applies, then count the number of certified sets needed before work starts, because extra sets restart the certification steps, then confirm with the receiving body whether it wants an original, a certified copy or a certified translation. Foreign documents used in a work permit or incorporation file — degrees, experience letters, the parent company's certificate of incorporation, powers of attorney and passports — must be translated into Thai or English as the office requires and certified along the correct chain: certification in the country of origin, then embassy or Department of Consular Affairs legalisation as applicable. Thailand deposited its instrument of accession to the Apostille Convention on 30 June 2026, but the Convention is not yet in force for Thailand, so embassy and Department of Consular Affairs legalisation remains the working route. ILC handles the document side only — certified translation, notarial signature certification and legalisation runs at the Department of Consular Affairs or an embassy. ILC is not the deciding authority and cannot guarantee an approval. Cost and lead time depend on page count, language pair and the certification steps the receiving authority requires, so every file is quoted before work starts. Send the checklist you were given, the applicant's nationality and the office you will file with via LINE @NAATI, call +66 80-557-8887 or email ilc@thainotary.co.th.

ปรึกษาฟรี — LINE @NAATI · โทร 080-5578887 · อีเมล ilc@thainotary.co.th