Marriage Allowance Calculator

How Marriage Allowance works

What is Marriage Allowance?

Marriage Allowance lets one partner in a marriage or civil partnership transfer up to £1,260 of their Personal Allowance to the other. This reduces the recipient's tax bill by up to £252 a year — because the transferred amount is taxed at the basic rate of 20%, and £1,260 × 20% = £252.

The benefit only arises where the lower earner has unused Personal Allowance (i.e. their income is below £12,570) and the higher earner is a basic rate taxpayer. It is not a cash payment — it simply shifts some tax-free allowance from one partner to the other, reducing the couple's combined tax bill.

Who qualifies?

To claim Marriage Allowance you must be married or in a registered civil partnership. Cohabiting couples do not qualify. The lower earner's income must be below the Personal Allowance of £12,570 (2026/27). The higher earner must be a basic rate taxpayer — meaning their income is between £12,571 and £50,270. If the recipient earns above £50,270 and pays 40% tax, Marriage Allowance is not available, as the allowance is only ever taxed at 20%.

How to apply

The lower earner applies — not the recipient. You apply online through the HMRC website (gov.uk/apply-marriage-allowance). The process takes around 10 minutes, and you will need both National Insurance numbers. Once approved, it is automatically renewed each year, so there is no need to reapply. If you prefer, you can also claim by phone (0300 200 3300) or by post.

Backdating your claim

You can backdate a Marriage Allowance claim by up to four tax years. In 2026/27 that means you can go back to 2022/23. Each backdated year adds a further £252 saving (at current rates), giving a potential lump sum of £1,008 for the four prior years. The backdated saving is applied as a reduction to the recipient's tax bill, or as a cheque if they have already paid the relevant tax.

When it makes sense to reconsider

Once you have elected for Marriage Allowance, HMRC automatically renews the arrangement each year. However, circumstances change. If the lower earner's income rises above £12,570 — for example, they return to work or start receiving pension income — they will begin paying tax themselves and the election should be cancelled. Similarly, if the higher earner moves into the 40% band (income above £50,270), they will no longer qualify as a recipient and the election must be cancelled. You can cancel through your HMRC online account at any time.