Op, not think to mut.
Open offshore uk bank account jersey/ Isle man.
using your new Thai address. ( as you are non uk resident now )
pay all money into that account, transfer money once a year to Thailand.
( only transfer money earned the previous tax year) no Thai tax to pay.
You get to keep any interest tax free from offshore account. ( as non uk resident, offshore uk account, non Eu resident)
Don't need any Thai tax number bs. no dual tax agreement bs.
stay out there systems as long as possible.
you get 12,750 tax free allowance in uk on money earned there, ( 2023 tax year )
pay Uk tax on what's left.
Well that's what I do. for about the last 10 years.
Ps You may need a few bob to open the account and you will be subject to there max payout if bank fails, think its 150,000.
Your funds will also be subject to there probate laws if you die. ( you need to look at that ) under 10,000
maybe ok for uk mainland will. over that, expensive !!
Not telling you to do this, but could be a goer for you.