Marriage Allowance UK 2026/27: Eligibility, Backdating Rules, and How to Claim

Every year, an estimated two million eligible couples in the UK miss out on free tax relief because they have never heard of Marriage Allowance or assume they do not qualify. If you are legally married or in a civil partnership, and one partner earns less than the Personal Allowance while the other pays tax at the basic rate, HMRC lets you transfer part of that unused allowance to lower your household tax bill. You can check your exact household saving in seconds using our Marriage Allowance calculator. Below is our guide to how the transfer works, who qualifies, how to backdate your claim for up to £1,260, and how to avoid fee-charging claim firms.

What is Marriage Allowance and how it works

Marriage Allowance was introduced under section 55A of the Income Tax Act 2007. It provides targeted tax relief to single-earner and single-main-earner couples where one partner earns less than the Personal Allowance.

Under the UK tax system, each adult gets a tax-free Personal Allowance of £12,570 for 2026/27. If you earn less than this, any unused allowance is normally lost. Marriage Allowance lets the non-taxpayer transfer 10% of their statutory Personal Allowance (£1,260, rounded to the nearest £10) to their spouse or civil partner.

When the transfer takes place, the lower earner's allowance falls from £12,570 to £11,310, and the higher earner's allowance increases from £12,570 to £13,830. Because the recipient pays the 20% basic rate on earnings above the allowance, shielding £1,260 from tax saves them exactly £252 each year (£1,260 multiplied by 20%). For PAYE employees, HMRC updates their tax code with an “M” suffix, cutting monthly deductions by about £21. To see the impact on your monthly pay packet, try our take-home pay calculator. If the recipient is self-employed, HMRC deducts £252 from their annual Self Assessment balancing payment.

Eligibility criteria for 2026/27

To claim Marriage Allowance, both partners must satisfy four statutory conditions during the tax year:

• Legal marriage or civil partnership: You must be legally married or in a civil partnership. Cohabiting couples do not qualify under any circumstances, regardless of how long you have lived together.
• Lower earner income: The transferring partner must normally have an annual income of £12,570 or less. This includes wages, pensions, and taxable state benefits. Non-taxable income like Child Benefit or ISA interest does not count.
• Higher earner income: The receiving partner must have an annual taxable income between £12,571 and £50,270 (in England, Wales, and Northern Ireland), paying tax at the 20% basic rate. Higher rate (40%) and additional rate (45%) taxpayers cannot receive the transfer. Check your band with our Income Tax calculator.
• Scottish taxpayers: In Scotland, where rates are devolved, the receiving partner qualifies if their taxable income is between £12,571 and £43,662 (Starter, Basic, or Intermediate rate), but not the Scottish Higher rate (42%). The annual relief is still £252.

Backdating your claim: how to get up to £1,260

HMRC allows you to backdate a Marriage Allowance claim for up to four previous tax years, alongside the current tax year. If you met the qualifying conditions in earlier years, you can claim the full backlog in one go.

For claims made in the 2026/27 tax year, you can claim for the current year and the four prior tax years:

When you submit a backdated claim through GOV.UK, HMRC pays the prior years' relief directly to the recipient partner as a lump sum refund by bank transfer or cheque. The current year's relief is applied to their tax code. If you qualified across all five eligible years, you could receive a combined £1,260.

The lower earner tax trap explained

While Marriage Allowance benefits most single-earner households, there is a scenario known as the lower earner tax trap. This happens when the lower earner has some income, but less than £12,570.

Because the transfer reduces the lower earner's allowance to £11,310, earnings between £11,310 and £12,570 become taxable at 20%. This creates a small tax bill that partially offsets the partner's £252 saving.

Here is a worked example with real numbers. Suppose Partner A earns £11,500 and Partner B earns £32,000:

• Partner A transfers £1,260, lowering their allowance to £11,310.
• Partner A now has taxable income of £190 (£11,500 minus £11,310). At 20%, Partner A owes £38 in Income Tax.
• Partner B gains £1,260 in tax-free allowance, saving £252 in tax on their salary.
• Net household saving: £252 saved minus £38 paid equals £214 net gain.

In this case, claiming still makes financial sense. However, if Partner A earns exactly £12,570, their extra £252 tax bill cancels out Partner B's saving entirely. Our Marriage Allowance calculator checks this automatically to confirm your true net saving.

Marriage Allowance vs Married Couple's Allowance

Marriage Allowance is often confused with Married Couple's Allowance. They are separate schemes with distinct rules.

Married Couple's Allowance is a legacy relief that applies only where at least one partner was born before 6 April 1935 (aged 91 or older in 2026). It reduces tax bills by between £457 and £1,150+ per year. You cannot claim both reliefs. For couples married today where both partners were born after 6 April 1935, Marriage Allowance is the only applicable scheme.

How to claim directly via HMRC without fees

Claiming Marriage Allowance is free and takes under ten minutes on GOV.UK. Never use commercial claim firms that take up to 40% or 50% of your rebate for submitting the same basic form.

• Have details ready: Both National Insurance numbers, your marriage or civil partnership date, and ID for the lower earner.
• The lower earner must apply: HMRC requires the partner giving up the allowance to make the application via their Government Gateway account at gov.uk/marriage-allowance.
• Select backdated years: Tick each earlier tax year in which you were eligible. HMRC calculates the rebate and transfers the funds to your bank account.
• Check tax codes: The lower earner gets tax code 1131N, while the higher earner receives 1383M.

For more on tax deductions, see our guide to UK Income Tax bands and rates and try our National Insurance calculator. If your household receives family support, our UK Child Benefit guide and Child Benefit calculator show how statutory allowances interact with the High Income Child Benefit Charge.

Common Marriage Allowance mistakes to avoid

• Using fee-charging claim firms: Third-party sites charge high commissions for a service that is completely free on GOV.UK. Always claim directly with HMRC.
• Assuming cohabitation qualifies: Cohabiting couples are not eligible under UK tax law. You must be legally married or in a civil partnership.
• Failing to notify HMRC when income changes: If the higher earner moves into the 40% higher rate band, you must tell HMRC to avoid a repayment demand later.
• Overlooking the lower earner tax trap: If the lower earner earns close to £12,570, transferring allowance can trigger an offsetting tax bill. Check your figures before applying.
• Missing the four-year backdating deadline: HMRC enforces a strict four-year limit. Each 5 April, the oldest eligible tax year expires permanently.

If either partner is self-employed, our self-employed tax guide explains how allowances and expenses interact on Self Assessment returns.

Frequently asked questions