How can I obtain a reentry permit at the airport when flying to Phnom Penh?

@Frans *****

All re-entry permits are only valid for as long as the stamp you purchase them for. So for example if you entered with a visa and received a 90 day stamp, the re-entry permit you purchase will only last until that stamp ends, not very long. But if you just got your 1-year extension and purchase a re-entry permit, it will last for a year. So this is one factor in which one you want to purchase.

A single re-entry permit means you can leave one time and return on your same stamp you have in your passport. If you wanted to leave again you would have to purchase another re-entry permit.

A multiple re-entry permit means you can leave and return and unlimited number of times until your stamp expires.

A re-entry permit does not give you any extra time in Thailand. The date of your entry stamp remains the same and will continue ticking down while you are outside of Thailand.

A single re-entry permit costs 1000 baht (1200 at the airport) and the multiple re-entry permit is 3800 baht (4000 at the airport).

So basically if you are going to leave 4 times or more during the validity of your stamp, it makes sense to purchase a multiple re-entry permit to save yourself time and possibly money.

One final factor to consider is the space in your passport. A re-entry permit is a large stamp, so if you are running low on pages, even if you are just planning on leaving 2 times, it may make sense to purchase a multiple re-entry permit so you only take up 1 page of your passport with the re-entry permit.