Why there is no apostille
Thailand is not a party to the Apostille Convention, so the single-certificate shortcut used between member states is not available here. Documents follow the older, longer route instead, and a foreign institution asking you for an apostille simply needs to be told what the Thai equivalent chain is.
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.