I have a 90 day non-b visa approved online by the London embassy, I’m a UK passport holder. To apply for the visa I put in arrival details for a direct flight from London to Bangkok. These details aren’t on the visa document issued and I’m looking at changing my travel plans. Would it be an issue if I flew in from another country, ie Singapore or Malaysia? Thanks!
TLDR : Answer Summary
You can change your travel plans and fly into Thailand from another country (like Singapore or Malaysia) without any issues, as long as your arrival is still within the validity period of your Non-B visa.