@Kaila **********

A multiple entry non B visa allows unlimited entries until its expiry date, and on every entry you receive a permission of stay of 90 days. So if the visa expires on March 10th and you enter let's say on March 8th, you will receive a permission of stay admitted until June 7th

Yes

@Valère ************************

i am aware she is not on an extension of stay

You cannot extend the permission of stay from a multi nonB for 30 days. You can extend for 12 months for work purposes with all the supporting documents required. In your situation it's best to exit Thailand and reenter before or on March 10th, and doing so you will receive another 90 day permission of stay.

@Ron ******

can you explain to me how they would check the criminal database in one's home country?

But Andy Steele, why don't you just cancel your trip to Laos. You will incur a small loss but then again I'm guessing you're not going there for the wonderful attractions Vientiane has to offer. And get your SETV back in the UK. Or apply for METV.

Steve Greir He's not going direct from Laos to the UK. He wants to enter Thailand and leave from here. Once he enters Thailand, his visa becomes used, so he needs a reentry permit to keep his permission of stay valid.

I have seen this being asked on ThaiVisa. My opinion is that the IO will not process him visa exempt with a valid SETV in his passport. But he can by all means ask.

Steve Greir Yes, the visa is valid for 90 days, and once you use it to enter it becomes invalid / used. Upon entry, you receive a permission of stay of 60 days. It's the permission of stay that you apply the re-entry permit for.

Andy Steele In your situation. Before you leave for the UK, get a reentry permit (single), from local Immigration or airport, that will allow you to return within those 60 days, and once you are back, extend that permission of stay for a further 30 days at local Immigration.

Your visa allows a permission of stay of 60 days upon entry. That is extendable for a further 30 days at immigration. If you want to keep your permission of stay valid, you must apply for a re-entry permit. You can apply for one both during the initial 60 days or while on the extension.

Maybe it's different in other countries. When i changed mine they asked me if i want it cancelled then or when i pick up the new passport and i chose the latter.