Marriage Allowance lets a non-taxpayer transfer £1257 of their personal allowance to a basic-rate-taxpayer spouse or civil partner, cutting the couple's tax by up to £251 a year in 2025/26. You qualify if one of you earns below the £12,570 allowance and the other pays basic-rate (not higher-rate) tax. Claims can be backdated up to four tax years.
What Marriage Allowance is
Marriage Allowance lets the lower-earning partner in a married couple or civil partnership transfer £1,257 — 10% of the £12,570 personal allowance — to the higher earner. That gives the higher earner £1,257 more tax-free income, saving the couple up to £251a year (20% of the transfer). It shows up as a changed tax code: the recipient’s code gains an M suffix, the giver’s an N.
Who’s eligible
- You’re married or in a civil partnership (living together unmarried doesn’t count).
- One partner earns less than the £12,570 personal allowance — so isn’t using all of it.
- The other partner is a basic-rate taxpayer (income between £12,570and the higher-rate threshold). If they pay higher-rate tax, you can’t claim.
How to claim
The lower earner makes the claim, free, through gov.uk or their personal tax account — never through a paid third-party site. Once approved, HMRC adjusts both tax codes and the saving flows through automatically each payday. It renews each year until you cancel it or your circumstances change.
The four-year backdate
If you were eligible in earlier years but never claimed, you can backdate the claim up to four tax years. That can turn a £251annual saving into a lump sum of several hundred pounds — a £251-a-year relief claimed with four years’ backdating is worth well over £1,004in total. It’s one of the highest-value few minutes you can spend on gov.uk.
See the effect on your take-home
A marriage allowance transfer shows up as a higher tax code (1257L becomes 1383M or similar). Enter yours in the calculator to see the change.
Open the calculator