Marriage Allowance UK: How to Transfer Your Personal Allowance and Cut Your Tax Bill

The Marriage Allowance is a tax relief that allows one spouse or civil partner to transfer a portion of their personal allowance to the other — saving up to £252 per year in income tax. It's relatively straightforward in principle, but there are eligibility conditions that many couples don't realise they need to meet, and the backdating rules mean couples who've never claimed may be owed several years of refunds.

How the Marriage Allowance works

Every UK taxpayer receives a Personal Allowance — the amount of income they can receive before paying income tax. For 2026/27, the personal allowance is £12,570.

The Marriage Allowance allows one partner (the transferor) to transfer £1,260 of their personal allowance to the other (the recipient). The effect:

• The transferor's personal allowance reduces from £12,570 to £11,310
• The recipient's personal allowance increases from £12,570 to £13,830

The recipient pays income tax on £1,260 less income per year. At the basic rate of 20%, this saves £252 per year (£1,260 × 20%).

The saving is £252 — no more, no less. It's not proportional to income and it doesn't compound. It's a flat annual saving at the basic rate.

Who is eligible

The Marriage Allowance has specific eligibility conditions. Both must be met:

1. You must be married or in a civil partnership. Unmarried partners (including long-term cohabitants) cannot use the Marriage Allowance. The allowance is specifically for those who have legally married or entered a civil partnership.

2. Income conditions:

• The transferor (the one giving up allowance) must have income below the personal allowance (below £12,570 for 2026/27). If the lower-earning partner's income is above £12,570, they are already using their full personal allowance and cannot afford to give any away.
• The recipient (the one receiving the transferred allowance) must be a basic rate taxpayer — earning between £12,570 and £50,270 in 2026/27. If the recipient is a higher rate taxpayer (earning above £50,270), they are not eligible.

The allowance is specifically designed for couples where one partner has very low income (or no income) and the other earns in the basic rate band.

Common scenarios where it applies

Classic scenario: One partner is employed and earns £35,000. The other partner has a small part-time income of £8,000 or cares full-time for children and has no income at all. The low-income partner transfers £1,260 of their personal allowance to the higher earner, who saves £252 per year.

Self-employed scenario: A freelancer earns £45,000. Their spouse earns £9,000 from a part-time job. The spouse's income is well below the personal allowance, so they qualify to transfer. The freelancer is a basic rate taxpayer (under £50,270), so they qualify to receive. The couple claims the Marriage Allowance and saves £252/year.

Scenario where it doesn't apply: Both partners earn £60,000. Neither is a basic rate taxpayer, so neither qualifies as the recipient.

Scenario where it doesn't apply: One partner earns £20,000. Their spouse earns £65,000. The spouse's income exceeds the basic rate threshold (£50,270), so they cannot be the recipient.

How to claim

The person who has the lower income (the transferor) makes the claim through HMRC's online Marriage Allowance application at gov.uk/apply-marriage-allowance. You'll need:

• Both partners' National Insurance numbers
• Proof of marriage or civil partnership

The claim can be made online in minutes. Once approved, HMRC adjusts the tax codes for both partners. If you or your partner are employed, the employer will receive an updated tax code and the benefit will flow through payroll automatically. If you're self-employed, it will appear as a reduction in your Self Assessment tax bill.

Use the Marriage Allowance Calculator to confirm your eligibility and see the exact saving.

Backdating your claim

One of the most valuable aspects of the Marriage Allowance is that you can backdate a claim by up to four tax years. If you were eligible in previous years but didn't claim, you can receive the saved tax as a repayment.

For 2026/27, you can backdate to:

• 2025/26
• 2024/25
• 2023/24
• 2022/23

The maximum backdated saving across four years would be approximately £1,008 (four years × £252). In practice, the annual saving varies slightly between years because of changes to the personal allowance — but £250 per year is the rough figure.

When you apply online, HMRC's system will typically ask if you want to backdate and process the refund automatically. The repayment is made to the recipient's bank account (or reduces their tax bill).

What happens when circumstances change

Divorce or dissolution of civil partnership: The Marriage Allowance automatically ceases at the end of the tax year in which the marriage or civil partnership ends. No action is required — HMRC adjusts tax codes from the following April.

Death of a partner: If the recipient partner dies, the transferor is still entitled to the Marriage Allowance for the full tax year in which the death occurred. If the transferor dies, the recipient retains the increased personal allowance for the remaining portion of the tax year.

Income changes: If the lower-earning partner's income rises above the personal allowance, they should cancel the transfer (through HMRC online). Continuing to transfer when both partners are using their full allowances doesn't cause an immediate error — but the transferor will pay slightly more tax than necessary without receiving the offsetting benefit, because their own personal allowance has been reduced.

The Married Couple's Allowance (different!)

The Marriage Allowance is sometimes confused with the older Married Couple's Allowance, which is a different and separate relief available only to couples where at least one partner was born before 6 April 1935. If either partner meets this condition, the Married Couple's Allowance may apply instead of (or as well as) the Marriage Allowance, and it is more valuable (£4,280 to £10,660 for 2026/27).

The Married Couple's Allowance operates as a credit at 10% rather than a transfer of allowance.

If you don't qualify for the Married Couple's Allowance (because both partners are born after 1935), the standard Marriage Allowance is the relevant relief.