The route that applies today
For now a paper leaving Palermo for Thailand takes two stamps, not one. An Italian authority confirms the signature; the destination's mission in Italy then confirms the Italian mark. That second confirmation is what makes a file usable at the far end, and document legalisation for Thailand cannot skip it while the current rules stand.
Why 28 February 2027 matters here
The accession year on record for Thailand is 2027, and the treaty begins to operate there on 28 February 2027. That is the single date this page turns on. A file finished before it needs both stamps; a file finished after it needs one. Nothing else about your paper changes — the same original, the same desk in Palermo, the same €16 stamp — only the second half of the journey. So the apostille requirements for Thailand come down to one mark after that day and two before it.
The Palermo end of the job
Sicilian records come from the same kinds of offices as records anywhere in Italy, and they follow the same national split. Anything signed by a public official at a comune, a school or a health office is administrative and goes to the Prefettura. Anything signed by a notary or issued by a court goes to the Procura della Repubblica. Getting that choice right first time is the cheapest thing you can do here.
How long to allow from Sicily
Give the Italian desk its own time, then give the mission its own, then add the trip in between. That third element is what makes an apostille from Italy to Thailand feel slower when it starts in Palermo: the island leg is real and it lands squarely in the middle of the chain. After the switchover the middle leg vanishes along with the consular stamp.
Three things that send a file back
A photocopy with no live signature is the first, because the Italian desk has nothing to match it against. A missing tax stamp is the second, and it stops the paper at the counter rather than later on. A translation bolted on after the marks are already there is the third, and it is the dearest of them, since the bundle has to go round again from the start.