Can I change my Non-Immigrant O visa dates or do I need to explain at immigration upon arrival?

@Colin ********

yes, but what I said is, the visa is only good for ONE entry (single entry visa class) so the visa itself will become invalid for further use after he entered Thailand. He then is in Thailand on a "90-days stay permit", and this stay permit can get extended for one year, if he fulfills the requirements. A visa cannot get extended. Buriram Immigration now uses the correct terminology, they don't "extend visas" any more. They fully correctly only extend "stay permits" 😎

@Stuart ********

thanks for your info...may be you know if canadian passport holder can apply for this visa at penang or kuala lumpur consulate?

@Philippe ********

Yes they can. Although it’s online application you have to be in that country to apply

@Stuart ********

I guess passport expiration date must be more than one year at the date of entry in thailand?

@Philippe ********

when you extend a non O for a year you need to have at least a year on your passport or else they will only extend to the expiry date of your passport. Get a new passport and don’t waste time on things like this

@Philippe ********

Thailand doesn’t actually have a limit of how long your passport is valid for but airlines almost certainly won’t let you board if you have less than 6 months left on a passport.