Can a Friend Use an Affidavit for 800K THB Balance for Visa Extension in Thailand?

If his consulate issues the affidavit of income from abroad, he could use it for ALL the monthly income requirements (IF he gets 65K baht a month) OR he can use it with banked money to meet the requirements by the combination method (part banked, part income).

Remember the banked portion of the money is subject to the seasoning rules (has to be in the account for 2 months before he applies has to stay in the account for 3 months after the extension is granted and can't go below 50% of the original amount the rest of the year).

Also remember not every office will accept the combination method (even though it IS written into the current police order) so check with the office before needing the extension.