Marriage Allowance is a UK tax relief that lets married couples and civil partners transfer part of their unused Personal Allowance between them, potentially reducing their combined tax bill by up to £252 a year. Despite this being a straightforward and valuable saving, HMRC estimates that millions of eligible couples in the UK do not claim it.
This article explains how Marriage Allowance works, who is eligible, and how to claim — including backdating a claim for previous tax years.
What is Marriage Allowance?
Every UK taxpayer has a Personal Allowance — the amount of income you can earn each tax year before paying income tax. The current Personal Allowance is £12,570 (check gov.uk for the current figure, as this is reviewed periodically — see our guide to the Personal Allowance for more detail).
If one partner in a marriage or civil partnership earns below the Personal Allowance and does not use all of it, Marriage Allowance lets them transfer up to 10% of their unused allowance — currently £1,260 — to their spouse or civil partner. The receiving partner gets a reduction in the amount of tax they owe, worth up to £252 per year at current rates.
Who is eligible for Marriage Allowance?
To qualify for Marriage Allowance, several conditions must be met. You must be married or in a civil partnership — simply living together does not qualify. The lower-earning partner must have an income below the Personal Allowance, meaning they pay no income tax or have unused allowance. The higher-earning partner must be a basic rate taxpayer, meaning their income falls within the basic rate tax band. If the higher earner is a higher or additional rate taxpayer, the couple does not qualify for Marriage Allowance.
Both partners must also have been born on or after 6 April 1935 — couples where one partner was born before this date may be entitled to the separate Married Couple's Allowance instead, which works differently and is generally more generous.
How much can you save?
The exact saving depends on the current Personal Allowance and the percentage that can be transferred. At present, the maximum transfer is £1,260, which reduces the receiving partner's tax bill by 20% of that amount — £252 per year. This amount can change if the Personal Allowance changes, so always check the current figure at gov.uk before claiming.
How to claim Marriage Allowance
You can apply for Marriage Allowance online through gov.uk. The application must be made by the partner with the unused allowance — the lower earner — rather than the partner who will benefit from the tax reduction. You will need both partners' National Insurance numbers, and one form of identification for the applicant such as their passport number, the last four digits of their bank account, or details from a P60.
Once approved, the allowance transfer is usually reflected through a change to the receiving partner's tax code if they are employed, or through their self-assessment tax return if they complete one. The allowance automatically renews each year unless your circumstances change or you cancel it.
Backdating your claim
One of the most valuable features of Marriage Allowance is that you can backdate a claim for up to four previous tax years, provided you were eligible in those years. This means a successful backdated claim covering the maximum period could be worth over £1,000 in total, paid as a lump sum or tax code adjustment.
To backdate, simply include the relevant tax years in your application at gov.uk. HMRC will calculate the amount owed for each eligible year.
What if your circumstances change?
If your income changes such that you no longer meet the eligibility criteria — for example, if the lower earner's income rises above the Personal Allowance, or the higher earner moves into the higher rate tax band — you should cancel the Marriage Allowance claim. Continuing to claim when no longer eligible can result in being asked to repay the relief, sometimes with interest.
If your marriage or civil partnership ends, Marriage Allowance also needs to be cancelled, though it can usually continue until the end of the tax year in which the relationship ends.
Marriage Allowance vs Married Couple's Allowance
These are two different reliefs and are easily confused. Marriage Allowance, covered in this article, applies to most couples and transfers part of the Personal Allowance. Married Couple's Allowance is a separate, generally more valuable relief available only where at least one partner was born before 6 April 1935. You cannot claim both at the same time.