if I read correct , 400k or 40k incoming every month. that's what I found in thai embassy uk website.
To stay with Thai family residing in Thailand
Biodata page of Passport or Travel Document
Photograph taken within the last six months
- If the photograph does not reflect your current appearance you may be refused to enter the Kingdom of Thailand.
Document indicating current location
- Applicant’s local utility bills (shows your name and address) e.g. electricity bill/ gas / mobile phone / rental agreement.
Financial evidence showing monthly income of no less than 40,000 THB (£1,000) or having the current balance of 400,000 THB (£10,000), e.g. bank statements, proof of earnings
- Applicant’s recent official UK/Ireland bank statement shows your name, address (Screenshots are not accepted). For monthly income of last 3 months no less than £1,000/ month.
Personal details of a family in Thailand, e.g. ID card, Passport
Proof of relationship to a family in Thailand, e.g. A copy of marriage certificate / birth certificate / certificate of adoption