What do I need to acquire in the UK for a spouse visa to move to Thailand, and what is the procedure and timeline before I fly?

I don't need options, I'm not married to a Thai so it's of no consequence to me personally.

@Robert *****************

Yes, the Non Imm O visa is valid to use for 90 days from it's issue date

@Gregor *********

I didn't know you had to show a monthly income. I thought all you had to show to get the extension based on marriage to a Thai was a Thai bank account with at least 400k deposited.

@Robert *****************

while you can use original proofs of a monthly income of a minimum of 40,000 THB equivalent, for the application to the visa in the E-Visa system in the U.K., you will need a minimum of 400,000 THB in a Thai bank account in your name only, for the application on Immigration for the 12-months "extended stay permit based on being married to a Thai wife" - at least in the first year. Because the U.K. embassy in Bangkok does not issue an "income affidavit" any more, with which you in the past were able to fulfill the financial requirements for the application to the "1-year Extension of Temporary Stay Permit" (which some people call "marriage visa" but which isn't a "visa" at all but a stay permit). After you have collected 12 months consecutive month for month transfers from the UK to your Thai bank account of a monthly minimum of 40,000 THB, you can use the bank statement over these 12 months of transfers for the application to your second year Extension of Stay Permit

@Robert *****************

yes, you shouldn't apply for the 90-days Non-Imm-O family visa more than 3 months before you plan to fly