Marriage Allowance is one of the simplest tax breaks in the UK and one of the most overlooked — millions of eligible couples never claim it. If one of you earns under the personal allowance and the other is a basic-rate taxpayer, you can shift some unused tax-free allowance between you and pocket up to £252 a year, plus several years of backdated payments. It takes ten minutes to claim. Here is how it works in 2025/26.
- One partner transfers £1,260 of their unused personal allowance to the other.
- The receiving partner pays £252 less tax a year (20% of £1,260).
- One of you must be a non-taxpayer (income under £12,570), the other a basic-rate taxpayer.
- You can backdate four years — a first claim can be worth over £1,200.
How it works
Everyone has a £12,570 personal allowance — income they can earn tax-free. If one partner doesn't use all of theirs (because they earn less than £12,570), Marriage Allowance lets them transfer £1,260 of it to their spouse or civil partner. The receiving partner then has a bigger tax-free allowance, so they pay 20% less tax on that £1,260 — a saving of £252 a year.
Who qualifies
You can claim if all of these apply:
The lower earner is the one who applies, transferring allowance to the higher earner. Check the figures with the Marriage Allowance calculator.
The backdating bonus
This is the part that makes a first claim worthwhile. You can backdate Marriage Allowance by up to four tax years, provided you were eligible in each. Combined with the current year, a first successful claim can be worth over £1,200 as a lump sum — real money for a ten-minute form.
Tell HMRC if your circumstances change If the lower earner's income rises above the personal allowance, or the higher earner moves into the 40% band, you may no longer qualify and could end up owing tax. Marriage Allowance usually renews automatically each year, so let HMRC know if your situation changes to avoid a surprise bill.
How to claim
The lower earner applies, free, through the gov.uk Marriage Allowance service (you'll need both partners' National Insurance numbers and a way to verify identity). Once approved, the receiving partner's tax code changes to reflect the bigger allowance, and any backdated amount is paid as a refund or through an adjusted code. There is no need to reapply each year — it carries forward automatically until you cancel or stop qualifying.
Frequently asked questions
Up to £252 a year, by transferring £1,260 of personal allowance from a non-taxpaying partner to a basic-rate taxpayer. Backdating four years can add over £1,000.
Married couples and civil partners where one earns below the £12,570 personal allowance and the other is a basic-rate taxpayer (income £12,571–£50,270).
Yes, by up to four tax years if you were eligible, so a first claim can be worth over £1,200 including the current year.
Yes. Once granted it carries forward each year until you cancel it or stop qualifying, so tell HMRC if your income changes.
You no longer qualify, and continuing to claim could mean owing tax. Notify HMRC so the allowance is cancelled.
Figures are 2025/26 estimates. Claim free through gov.uk — you never need to pay a third party to apply for Marriage Allowance.