If one of you earns under the Personal Allowance and the other is a basic-rate taxpayer, you could be £252 a year better off — plus up to £1,008 backdated — just by ticking a box on gov.uk. This calculator checks your eligibility and shows the exact saving.
UK Marriage Allowance Calculator
Check if you can claim Marriage Allowance, how much you’d save this year, and whether you can backdate up to four years. 2025/26 rates.
Marriage Allowance lets a non-taxpayer transfer £1,260 of their Personal Allowance to a basic-rate-paying spouse or civil partner. The receiving partner pays less income tax — up to £252 saved in 2025/26.
—
What Marriage Allowance is
Marriage Allowance is a quiet little tax break that lets one spouse or civil partner transfer £1,260 of their unused Personal Allowance to the other, provided the lower earner doesn’t need it all themselves and the higher earner is paying tax at the basic rate. The receiving partner’s Personal Allowance jumps from £12,570 to £13,830, knocking 20% off £1,260 — a flat £252 saving per tax year.
It’s free to claim, takes about ten minutes online, and renews automatically year after year until your circumstances change. About 2 million UK couples are eligible but never claim — collectively leaving roughly £500 million on the table annually.
Who qualifies
- Married or in a civil partnership. Cohabiting couples cannot claim, regardless of how long they’ve been together.
- One partner earning at or under £12,570. This is the Personal Allowance for 2025/26 — the lower-earning partner cannot owe income tax on their own income for the transfer to make sense.
- Other partner is a basic-rate taxpayer. That means income between £12,571 and £50,270 in England/Wales/NI, or up to £43,662 in Scotland (the top of the intermediate rate band).
- Both born after 6 April 1935. Couples where at least one partner was born before that date use the older, more generous Married Couple’s Allowance instead.
Backdating is real money. You can claim Marriage Allowance for the four previous tax years if you were eligible then. That’s up to £1,008 in addition to this year’s £252.
How to claim
- The lower-earning partner applies. You can’t claim on someone else’s behalf. Both of you need a National Insurance number and a way to prove your identity (passport, UK driving licence, or recent payslip).
- Go to
gov.uk/marriage-allowance. The online claim is free — do not pay any third-party site that charges for it. - Submit and wait. HMRC typically updates both tax codes within 2–6 weeks. The receiving partner sees the saving via a lower in-year tax bill.
- Tick the backdated claim. When you apply, you’ll be asked whether you want to claim for prior years. Say yes — backdated savings come as a separate refund cheque or bank credit.
- Renew if you start the claim mid-year. The first year is pro-rated; from year two onward, it auto-renews until you cancel or one of you loses eligibility.
When it isn’t worth claiming
- Lower partner is on the edge. If the “lower” partner earns more than £11,310 (£12,570 minus the £1,260 transfer), they’ll start paying tax themselves on the bit they handed over. The household is usually still better off, but check the calculator carefully.
- Higher partner is just over the PA. If the higher earner only earns £13,000, the transferred allowance saves only the tax that was actually being paid (in this case, £86 — not £252). The calculator above shows the real number, not the headline maximum.
- You’re planning a major income change. If the higher partner will move into the higher rate next year (promotion, bonus, dividend windfall), the allowance is wasted. You can cancel any time.
Frequently asked questions
Do I have to apply every year?
No. After the initial claim, Marriage Allowance renews automatically. HMRC only stops applying it when you cancel, divorce, dissolve a civil partnership, or notify them that one partner’s income has moved out of the eligible range.
Will it affect my benefits?
Marriage Allowance changes how Personal Allowance is split between you, not your total taxable income. It has no direct effect on means-tested benefits like Universal Credit or Tax Credits.
What if my partner died?
If your spouse or civil partner died after the start of the 2020/21 tax year, you can still backdate a claim covering the years before their death. The claim is then closed out for current years.
What about Scottish taxpayers?
Scottish residents qualify if the higher-earning partner pays at the starter, basic, or intermediate rate — the upper limit is around £43,662 of income in 2025/26 (the top of the intermediate band). Above that, you’re a higher-rate Scottish taxpayer and the allowance is not available.
Why isn’t this just automatic?
HMRC doesn’t know which couples are married or in civil partnerships unless told. They could in theory cross-reference with the registrar, but historically have not — so the onus is on you to claim. There’s no penalty for claiming late, only for the years you miss.
More UK tax calculators
From take-home pay to side hustles to IR35, the calculators page collects every UK tax tool on the site.
