The apostille is coming — but is not yet in force
Thailand acceded to the Apostille Convention on 30 June 2026, and the Convention will enter into force for Thailand on 28 February 2027. Until that date the single-certificate shortcut used between member states is still not available here: Thai documents generally continue to follow the existing, longer legalisation route. A foreign institution asking you for an apostille today simply needs to be told what the current Thai chain is — and that the apostille itself becomes available from 28 February 2027.
Step one — certification by a notarial services attorney
Thailand has no notary public office; the equivalent function is performed by a lawyer registered with the Lawyers Council of Thailand as a notarial services attorney. The certification attests who signed, or that a copy matches the original — not that the contents are true, a distinction foreign authorities understand well.
Step two — the Ministry of Foreign Affairs
The Department of Consular Affairs legalises the document, and often requires a certified translation into Thai or English first. Each step in the chain checks the one before it, which is why an error made at step one is usually discovered here rather than immediately.
Step three — the destination embassy
Most destinations then require legalisation by their own embassy in Thailand. Requirements, formats and processing times vary by embassy and by season, and this stage is where deadlines are usually missed — not because it is difficult, but because it is the step nobody budgeted time for.
Ask the receiving body first
The chain that matters is the one your receiving institution requires, and it is often shorter or longer than expected. One email to them before you begin, and the whole sequence can be mapped and completed once — rather than discovered in stages, each time from the counter of an office that has just refused something.
What changes on 28 February 2027
Once the Convention is in force, a Thai public document going to another member state should need only a single apostille certificate from the designated Thai authority, in place of the consular legalisation chain — and public documents from member states should be accepted in Thailand the same way. The practical details, including which authority issues Thai apostilles and how the transition is administered, will be settled closer to the date, and documents destined for non-member states will continue to need legalisation. If your matter straddles the changeover, ask us which route your document should take.