Marriage Allowance: How to Claim and Backdate Your GBP 252 Tax Break 2026

Marriage Allowance is one of the most underused tax reliefs in the UK. Millions of eligible couples still have not claimed it, leaving GBP 252 a year -- and potentially over GBP 1,000 in backdated relief -- uncollected. If you are married or in a civil partnership and one of you earns below the Personal Allowance, this guide explains exactly what you need to do.

What Is Marriage Allowance?

Marriage Allowance allows the lower-earning partner to transfer GBP 1,260 of their Personal Allowance to the higher-earning partner. In 2026/27, the Personal Allowance stands at GBP 12,570. The transfer reduces the lower earner's allowance to GBP 11,310, while the higher earner receives a tax credit worth GBP 252 (20% of GBP 1,260).

This is not a deduction from taxable income -- it is a direct reduction of the tax bill. That makes it straightforward to value: the higher earner saves GBP 252 in income tax per year.

Who Is Eligible?

To qualify, both of these conditions must be met:

1. You are married or in a civil partnership (cohabiting couples do not qualify).
2. One partner earns below the Personal Allowance of GBP 12,570, and the other is a basic-rate taxpayer -- meaning their income is between GBP 12,571 and GBP 50,270.

The relief is not available if either partner pays tax at the higher rate (40%) or additional rate (45%). If the receiving spouse earns above GBP 50,270, their income falls into the higher-rate band and the transfer does not apply.

The lower-earning partner can be earning nothing at all -- for example, they may be a carer, student, or part-time worker. The key is that their income falls below GBP 12,570.

How Much Can You Save?

In 2026/27:

• Annual saving: GBP 252
• Backdated claim (4 tax years): 2022/23, 2023/24, 2024/25, 2025/26 each attract their own amounts
• Total possible backdated refund: approximately GBP 1,260 depending on years claimed

HMRC allows you to backdate claims for the previous four complete tax years. If you have been eligible since 2022/23 and never claimed, you can receive four years' worth in a lump sum alongside the current-year allowance.

How to Claim

The simplest route is the HMRC online service at gov.uk/apply-marriage-allowance. You will need both partners' National Insurance numbers and the applicant's Government Gateway login. The lower earner must be the one to initiate the claim -- the receiving partner cannot apply on the other person's behalf.

If the higher earner is employed, the allowance is normally applied through a change to their PAYE tax code. HMRC adjusts the code to reflect the GBP 1,260 credit, and the saving comes through in monthly payslips. For self-employed people or those who file Self Assessment returns, the credit is applied through the annual tax return instead.

Once you claim, the allowance continues automatically each year until one of you cancels it or your circumstances change. You do not need to reapply annually.

Backdating Your Claim

When you submit a claim, HMRC automatically looks back at earlier years. For each eligible prior year, the refund is paid directly to the higher earner -- typically as a cheque or bank transfer. The processing time is usually two to four weeks, though it can take longer during busy periods.

It is worth noting that if the higher earner has died, the surviving spouse can still claim Marriage Allowance for the years before death, including backdated years. HMRC has a specific process for this situation.

Common Mistakes to Avoid

A few errors catch people out:

• Applying when the receiving partner earns above GBP 50,270. The credit does not apply in higher-rate tax situations.
• Confusing Marriage Allowance with Married Couple's Allowance. The latter is a separate, older relief for couples born before 6 April 1935 and operates differently.
• Forgetting to cancel if circumstances change. If the lower earner's income rises above GBP 12,570 mid-year, they should notify HMRC to avoid an unexpected tax bill.

When It Is Not Worth It

If the lower-earning spouse has income between GBP 11,310 and GBP 12,570, transferring the allowance might push some of their income into the taxable band. In practice, the net saving for the household is still GBP 252 as long as the higher earner remains a basic-rate taxpayer, but it is worth checking your figures first.

Check Your Take-Home Pay

Marriage Allowance is one of several factors that affect your net pay. Before or after you claim, it is useful to model how the change feeds through to monthly take-home figures.

Use the CalcHub Take-Home Pay Calculator to see exactly how Marriage Allowance affects your monthly and annual net income based on 2026/27 rates.