Apostille vs. Embassy legalisation for Thailand
A single shared certificate only works once both sides of a route have signed the same treaty and agreed to trust each other's paperwork. Short of that agreement being in force, a longer sequence takes over instead: a diplomatic mission adds its own approval on top of whatever certificate the origin country already produced. Thailand sits in an unusual middle position on this particular question, having signed the treaty without yet switching it on.
Thailand has signed the Hague Apostille Convention, but that signature does not switch anything on immediately. Today, an apostille for Thailand is not yet accepted there, so document legalisation for Thailand still runs through the fuller embassy route. From 28 February 2027, once the accession itself takes effect, a single certificate replaces that longer chain, and the embassy stage described below stops applying from that point on.
Thailand's Hague status & what it means
Thailand's accession to the Hague Apostille Convention enters into force on 28 February 2027; before that date the treaty simply is not operational between the two countries, no matter how firmly Thailand has already committed to it on paper. A signature and a working agreement are two different things, and only the second one lets a certificate stand alone without anything added afterwards.
What you need for an apostille for Thailand therefore depends entirely on the calendar. Before 28 February 2027, embassy or consular legalisation remains the only working route; from that date onward, the UK certificate becomes sufficient by itself, with the Thai side of the process dropping away for good once the accession takes effect.
The Edinburgh → Thailand route step by step
Wherever the underlying paperwork was first drawn up — an Edinburgh register, a court, a university, a company — the certifying step itself always runs through one address in England. An apostille issued in Edinburgh for use in Thailand is, once it is posted, processed at that single national office rather than locally, since the FCDO Legalisation Office covers the whole of the UK from one desk.
After that first certificate is attached, what happens next splits on the date. Sent before 28 February 2027, the item still needs a further stamp from the Thai embassy or consulate; sent on or after that date, the UK certificate alone is enough, and the extra stage simply falls away.
Cost & timing for this route
The UK certificate costs £45 per document under the standard postal service, or £40 per document where a registered business chooses the faster next working day lane instead, a lane closed to individual applicants. That figure holds steady whatever the destination and however many pages the paperwork runs to, so this UK charge does not shift depending on which side of 28 February 2027 an application falls.
Standard UK handling runs up to 25 working days, plus whatever time the item spends in the post on each leg, before the certificate is attached and returned. Before 28 February 2027 that UK timeframe is only the first stage, since the Thai embassy stage sets its own separate charge and its own separate timetable on top of it.
Destination-specific requirements
An apostille from United Kingdom to Thailand certifies the UK paperwork only, and that stays true whichever side of 28 February 2027 the application falls on. Before that date the item is unfinished until the Thai embassy or consulate adds its own stamp; from that date, the UK certificate closes the matter by itself, with no further stage to add.
Anyone applying near that boundary should note which date their paperwork is likely to be sent, since it is the only thing separating the shorter route from the longer one. Nothing about the underlying document itself changes between the two dates — only the process wrapped around it does, and that process resets cleanly once 28 February 2027 has passed.