Like zero if you paid tax in UK. BUT you’re supposed to fine it.
1. You file the amount you remitted into Thailand in your pnd
*****
form.
2. You deduct the amount of tax paid in UK under the field “foreign tax credit” in the form.
3. You end up with net zero tax owed.
But you still are legally required to actually file. Which gives you some serious benefits like legal compliance, ability to obtain Tax Residency, certificates, Safer Banking, Release from potential capital gains tax in other countries, discounts on dividends taxes. Etc etc