In the 2026/27 tax year, eligible UK couples can claim up to £252 in Marriage Allowance tax relief by transferring 10 per cent of one partner's personal allowance to the other. This benefit is available to married couples or civil partners where one partner earns at or below the £12,570 personal allowance and the other is a basic-rate taxpayer. Claims are made free of charge via GOV.UK and can be backdated by up to four previous tax years, potentially delivering a combined saving of approximately £1,260.

This tax break addresses a specific imbalance in the UK tax system, allowing couples to optimise their collective tax position. Millions of eligible couples have not yet claimed this allowance, missing out on significant savings.

What is the UK Marriage Allowance and how does it differ from other tax breaks?

Marriage Allowance is a UK income tax allowance enabling a non-taxpaying spouse or civil partner to transfer 10 per cent of their personal allowance to their basic-rate-taxpaying partner. For the 2026/27 tax year, the personal allowance stands at £12,570, a figure frozen since 2021/22 and expected to remain unchanged until 2027/28.

The transferable amount in 2026/27 is £1,260 (10 per cent of £12,570). This transfer directly reduces the higher earner's taxable income, leading to a reduction in their income tax liability. This mechanism differs fundamentally from the Married Couple's Allowance, which is a distinct and now largely obsolete tax relief available only to couples where at least one partner was born before 6 April 1935.

Marriage Allowance focuses on ensuring that couples with uneven incomes can still benefit from the full value of both partners' personal allowances, preventing the lower earner's unused allowance from being entirely lost.

Who is eligible for Marriage Allowance in 2026/27?

To qualify for Marriage Allowance, couples must meet three specific criteria, ensuring the relief targets those within certain income tax bands.

• Marital Status: Both partners must be either married or in a registered civil partnership. The allowance is not available to unmarried couples.
• Lower Earner's Income: The lower-earning partner must have a total annual income at or below the personal allowance. For 2026/27, this threshold is £12,570. This means they are not utilising their full personal allowance themselves.
• Higher Earner's Tax Rate: The higher-earning partner must be a basic-rate (20 per cent) income tax payer. In England, Wales and Northern Ireland, this means their income falls between £12,571 and £50,270.

Marriage Allowance does not apply where the higher-earning partner is a higher-rate (40 per cent) or additional-rate (45 per cent) income tax payer. If the higher earner's income exceeds the basic-rate band, the couple is not eligible for this relief.

How much tax relief can Marriage Allowance provide, and how is it calculated?

The financial benefit of the Marriage Allowance is straightforwardly calculated based on the transferable personal allowance and the basic rate of income tax.

For the 2026/27 tax year, 10 per cent of the £12,570 personal allowance amounts to £1,260. When this £1,260 is transferred to a basic-rate taxpayer, their income tax bill is reduced by 20 per cent of that amount. This translates to a maximum income tax saving of £252 (£1,260 multiplied by 20 per cent) for the tax year.

This annual saving can be substantially increased by backdating claims. Marriage Allowance claims can be backdated by up to four previous tax years. This means a claim made during the 2026/27 tax year can recover unclaimed allowances from 2022/23, 2023/24, 2024/25, and 2025/26, in addition to the current year's saving. The maximum combined value of such a claim, covering all five eligible tax years (2026/27 plus the four previous), is approximately £1,260 (five multiplied by £252). This lump sum can represent a considerable recovery for households.

How do you apply for Marriage Allowance and manage backdated claims?

The application process for Marriage Allowance is designed to be accessible and free of charge. The lower-earning partner is the individual who applies, initiating the transfer of their unused personal allowance.

Applications are made online via GOV.UK at the official URL gov.uk/apply-marriage-allowance. The process requires the National Insurance number for both partners to verify eligibility and process the transfer. HMRC does not charge any fee for this application.

Once a claim is made and approved, any backdated amount is paid as a single lump sum directly to the higher-earning partner. This ensures the immediate recovery of past savings. For the current tax year, the saving is applied through an adjustment to the higher earner's tax code, reducing their ongoing tax deductions at source. Estimates from published HMRC data and personal finance outlets indicate that approximately 4 million eligible UK couples have not yet claimed this allowance, highlighting a significant opportunity for tax relief.

How do Scotland's tax thresholds affect Marriage Allowance?

While the core principles of Marriage Allowance remain consistent across the UK, Scotland operates with devolved income-tax thresholds. These thresholds, including the basic-rate, intermediate and higher-rate bands, differ slightly from those in England, Wales and Northern Ireland.

For couples residing in Scotland, the eligibility test for the higher-earning partner, specifically regarding their status as a basic-rate income tax payer, uses these distinct Scottish bands. This means that while the personal allowance amount of £12,570 for 2026/27 is universal, the income range defining a basic-rate taxpayer for the purposes of Marriage Allowance eligibility will align with Scotland's specific tax structure.

What happens if your circumstances change or you need to cancel Marriage Allowance?

Once granted, Marriage Allowance continues to apply automatically year-on-year. However, certain changes in a couple's circumstances can affect eligibility or necessitate action.

If the lower earner's income rises above the personal allowance (£12,570 in 2026/27), or if the partners separate, divorce or are bereaved, the eligibility criteria may no longer be met. In such cases, the allowance may need to be adjusted or cancelled. Either partner can cancel the Marriage Allowance at any time by contacting HMRC directly. HMRC will then adjust both partners' tax codes accordingly from the next tax year.

Following the death of a partner, the surviving partner can still claim backdated Marriage Allowance for any tax years in which the couple was eligible while both partners were alive. This provision ensures that families can still recover past entitlements during a difficult period.

What should you do next?

Couples in the UK who believe they might be eligible for Marriage Allowance should verify their current income and marital status against the criteria for the 2026/27 tax year and previous years. Gather the National Insurance numbers for both partners. Proceed to the official GOV.UK website to submit an application, ensuring all relevant tax years are considered for backdating.