I don't know if the system is sophisticated enough to track your IP address, but the requirement is that one apples from ones home of record (in your case, the US). You can most certainly complete the application from Cambodia and it's possible a VPN will shield your location but with a non-refundable $200 fee you might hesitate at taking a chance.

If you are in Ireland, and supply your Irish passport number, you will be fine. Do note that your flight to Thailand must also originate from Ireland.

If your country of residence is in the UK you must apply from there. And the amount will have to have been in your UK bank account for the past 6 months. Once the visa has been approved you can spend it as you wish.

@Klaus **********

I've successfully applied for 3 METVs and have used "tourism and travel" as my reason.

@Paul ******

Please do!

I always write "travel and tourism".

Are you certain you cannot get a certificate of residence from the US consulate or embassy? I've gotten them numerous times from the consulate in Chiang Mai on visa exempt.

I stay 4-5 months annually. The METV seems a far better fit

Application

@Ivan ***********

I hope you're right about that. I know of two friends here in the US who were denied visas (METV) and both lost their $200 application fee. Thankfully I haven't after three applications.

@Ivan ***********

Thai consulate application sites state clearly that visa application fees are not refundable.