@Greg *******

They'd still need onward travel within 30 days

Your airline will want to see onward travel within 30 days, technically so do Immigration but they rarely ask to see it.

You DONT need to season the 800k for 2 months for the Non Imm O VISA. Seasoning is for the 1 year extention of stay. Why not get the Non Imm O evisa before you arrive?

@Carsten ***********

Get the visa at the visa office just before Immigration at Chong Sangam and Chong Chom crossings. Both crossings 1200bt. You can also get an evisa.

@Robert *****

1200bt for the visa.

@Felix *****************************

The visa on arrival for Cambodia is 1200bt. It gets you stamped in for 30 days.

Yep. The Chong Sangam border crossing is open.

@Stuart *********

That's for the visa. He needs legal custody for the guardian extention of stay. His marriage would overide the 'guardian' extention of stay.

@Stuart *********

He does indeed have 3 options, however the criteria you state is for yearly extentions of stay. The OP needs a Non Imm O visa first which he can obtain in the UK without the need for many of the criteria you list. Also his yearly extention of stay based on being a guardian would require him to go through the Thai courts to obtain full legal guardianship of his child.

@Chris ******

All that's for the extention NOT the Non Imm O visa. No need to tie up 800k in a Thai bank account.