A guy I know had his pension stopped twice because he changed address and didn't notify DWP. It was a pita to sort out, his son had to call UK for him in the end
This is what the UK gov website says about driving here
"If you are planning to drive in Thailand, see information on driving abroad. You’ll need to carry both the 1968 version of the international driving permit (IDP) and your UK driving licence while driving. You cannot buy an IDP outside the UK, so get one before you travel.
If you live in Thailand, you can apply for a Thai driving licence using your UK driving licence."
I have had 3 of these while living here, number 1 was signed by my GP - she charges for doing it. Number 2 was signed and stamped by reception in my condo and the third I have just had signed and stamped by the piya baan in my village.
1 and 2 accepted by DWP without a problem and I assume number 3 will be as well