iam due a 90day border run 19 april with a non o based on marriage I understand I could get 60 days to visit wife but could I put 400000 in the bank and get an extension based on marriage ? my visa does not run out until end of October. also does the 400000 have to come from abroad thanks

I presume you have a 1-year MultipleEntry Non Imm O - marriage Visa which is valid till end of October, and that your present 90-day permission to stay expires 19 April.

So you can either

- do a border-run before 19 April, which will provide you once again with a 90-day permission to stay,

- apply for a 60-day extension of stay at your local IO for reason of visiting your thai wife (no need for financials to be proven).

You can also apply for a 1-year extension of stay, but that requires that you have 400,000 THB on your thai bank-account already seasoned for 2 months before applying for that 1-year extension.

I attach UbonJoe's list which covers the full set of requirements for such 1-year extension application.

1122881058_MarriageExtensionRequirements2.pdf

You can apply for a one year extension of stay based upon marriage if you have 400k baht in a Thai bank for 2 months. There is no requirement for proof it came from abroad.