you couldn’t be more wrong, everything you just stated is demonstrably factually incorrect. There is a reason why tax credits exist in DTA’s. You need to do much more reading and research on the subject, suggest you join “Thailand tax for expats” group for some Thai tax insights.
it is certainly addressed. £32,287 income on a 1257L tax code provides £19,717 taxable income at 20% generating a UK tax payment of £3,943 resulting in a Thai tax credit of 167,160 baht at a FX rate of 42.39.
apples and oranges, different scenarios different results. I did mix the single and married rates though:
Single taxpayer payer £32,287
Married taxpayer £39,364
Basic UK rate taxpayer claiming the UK tax credit on their Thai tax return. Remitting more than the above amounts starts to actually raise a Thai tax bill.
using only the minimum Thai allowances of a single rate taxpayer of 60k, add on an income deduction of 100k for income from employment then add the first 150k zero rate gives you a net total of 310k before any Thai tax is due (approx £7200). Every penny over will start to attract a Thai tax bill. However by utilizing the UK DTA tax credit you can further reduce your Thai taxation. A basic rate UK tax payer (1275L) will have tax withheld at 20%. So you cancel out the Thai tax bands of 5%,10%,15% and 20% by claiming on your tax return the UK tax credit. You then get to the figure of approx £39k where all of your 20% tax credit is exhausted and you start dipping into the Thai 25% tax rate. This is just the minimum figures if you’re married or over 65 the figure will change. However you must register for a TIN and file a tax return to be able to claim your UK tax credit and it also assumes that all the remitted foreign sourced income has been taxed in the UK at the basic rate e.g. company or private pension payments.