Marriage allowance

Dazed_and_confused

I get MA which means the first (£12500*1.1=) £13750 is tax free. I get that

You have got that wrong.

Being a recipient of Marriage Allowance does not entitle you to any extra Personal Allowance.

Your Personal Allowance is £12,500 not £13,750.

But you are entitled to a tax credit of £250 (£1,250 x 20%) off your total tax liability.

Unless you have some gift aid payments or relief at source pension contributions to take into account your basic rate band will be £37,500.

Plus Personal Allowance £12,500 = £50,000 before higher rate tax becomes an issue.

I think you are confusing the tax code system, where HMRC include extra allowances in your tax code to ensure you receive the benefit of Marriage Allowance during the course of the tax year, with the reality of how your tax is actually calculated once the year is ended and the full facts/income is known.