Marriage Allowance Calculator
Whether a couple qualifies for Marriage Allowance, the £252 a year it saves, backdating up to four years, and when the Married Couple’s Allowance applies instead.
How it works
Transfer £1,260 of personal allowance (10%) from a partner earning under £12,570 to a basic-rate partner → 20% × £1,260 = £252 a year; backdate up to 4 years
Marriage Allowance lets a low earner hand a tenth of their unused personal allowance to a spouse or civil partner who pays basic-rate tax, worth £252 a year at current rates. Around two million eligible couples have never claimed. It can be backdated four years, so a first claim can bring over £1,000. If the lower earner’s income is between £11,310 and £12,570 they will pay a little tax on the transferred slice, reducing the net gain. Claims are made online by the lower earner and continue automatically.
Worked example
Incomes of £9,000 and £38,000: £1,260 transfers, the higher earner saves £252, the lower earner pays nothing extra, and two backdated years add £504 — £756 in the first year.
Frequently asked questions
Does it work if the higher earner is Scottish?
Yes, as long as they pay the starter, basic or intermediate rate (income up to £43,662).
What if we separate?
The transfer runs to the end of the tax year of the divorce or separation, then stops.
Related calculators
Uses 2025/26 UK rates and thresholds (England & Northern Ireland income tax unless stated). Thresholds change every April — check GOV.UK for the current figures. Educational estimate, not tax advice.