Marriage Allowance lets one partner give a slice of their unused Personal Allowance to the other. It is small, but it is also one of the few tax claims that costs nothing and can be backdated. It is easy to overlook, because it only works for a particular mix of incomes.
What it is worth
gov.uk's Marriage Allowance page says you can transfer £1,260 of your Personal Allowance to your husband, wife or civil partner. For a basic-rate taxpayer that reduces their tax by up to £252 in the tax year (£1,260 taxed at 20%). The tax year runs from 6 April to 5 April.
The giving partner's Personal Allowance falls by £1,260, so they may pay a little more tax. gov.uk warns about this and says you "might have to pay more tax yourself, but you could still pay less as a couple." Its own example has the lower earner starting to pay tax on £190 while the couple saves £214 overall.
Who qualifies
| Requirement | England, Wales, Northern Ireland | Scotland |
|---|---|---|
| Relationship | Married or in a civil partnership | Same |
| Giving partner | Lower earner with income below the Personal Allowance (usually £12,570) | Same |
| Receiving partner | Pays Income Tax at the basic rate, usually income of £12,571 to £50,270 | Pays the starter, basic or intermediate rate, usually £12,571 to £43,662 |
You do not qualify if you only live together without being married or in a civil partnership. You also cannot receive Marriage Allowance and Married Couple's Allowance together. gov.uk notes that if either of you was born before 6 April 1935, Married Couple's Allowance may be worth more. Receiving a pension, or living abroad, does not rule you out as long as you still get a Personal Allowance.
The 2025/26 Personal Allowance and the basic rate band are on HMRC's Income Tax rates and allowances page: a £12,570 Personal Allowance, and a basic rate band of £37,700 above it. That is where the £50,270 figure comes from (£12,570 plus £37,700).
How to claim
The giving partner applies using gov.uk's online service, and the receiving partner benefits through a lower tax bill. Once the claim is accepted, your Personal Allowance keeps transferring every year until you cancel, so you need to cancel or change the claim if your circumstances change. gov.uk gives a change in income or the end of the relationship as examples of changes to report.
If you already file Self Assessment, make sure the figures on your return match the claim you made. You do not need Self Assessment simply to claim.
Backdating
gov.uk says you can backdate a claim to 6 April 2022, the 2022/23 tax year, if you were eligible in those years. If your partner died after 5 April 2022, you can still claim by phoning the Income Tax helpline. The earliest year available can change, so check gov.uk before you rely on a particular date.
The legal route is an election under section 55C of the Income Tax Act 2007, which section 55D allows within four years after the end of the tax year and which then carries on from year to year until withdrawn. That four-year window is why the earliest year gov.uk accepts moves on each 6 April: 2022/23 can be claimed until 5 April 2027.
A backdated claim for several years can produce a worthwhile lump sum. The saving is capped at £252 a year, so four tax years at most come to £1,008 if you qualified in each of them; the actual figure depends on each year's income.
When Marriage Allowance is not the right claim
- Higher-rate partner. If the receiving partner pays tax above the basic rate, they are outside the rules and gain nothing.
- Both partners below the Personal Allowance. No one has tax to reduce.
- Lower earner above the Personal Allowance. The giving partner's income must be below it, so there is no unused allowance to transfer.
Marriage Allowance is also unrelated to the High Income Child Benefit Charge, which looks at the higher earner's adjusted net income.
Check before you claim
- Work out each partner's likely income for the tax year.
- Confirm the receiving partner is a basic-rate taxpayer.
- Use the take-home pay calculator to see each person's tax before and after.
- Claim online with gov.uk, and diarise any change to income that might end the claim.
How ac-co helps
ac-co drafts your SA100 from your bank, books and HMRC data, shows the full tax computation and files only after you approve it, so you can check that a Marriage Allowance claim shows up correctly in the tax figure you review before filing.