Marriage Allowance explained

What it does

Marriage Allowance is a fairly simple idea: one partner hands over £1,260 of their unused tax-free Personal Allowance to the other. Do the maths and that's worth £252 a year for 2026/27 — 20% of £1,260, since that's the rate it would otherwise have been taxed at.

It only actually helps if one of you isn't using your full allowance — typically because you earn under £12,570, or don't work — and the other earns enough to make use of extra tax-free income without tipping into higher-rate territory.

Who's eligible

The rules: you need to be married or in a civil partnership (living together doesn't count, however long you've been together), one of you earning below £12,570 or nothing at all, and the other sitting as a basic-rate taxpayer — under £50,270 in England, Wales and Northern Ireland, or the Scottish equivalent. Cross into higher-rate territory and the allowance stops being available for that year.

How it shows up on a payslip

Transfer your allowance away and your code picks up an N (1131N instead of 1257L). Receive one and yours gets an M instead. Both of you will notice your code change, even though only one of you actually sees a smaller tax bill.

Backdating and how to claim

Here's a bit most people miss: you can backdate a claim up to four tax years if you were eligible but never got around to it — potentially worth up to roughly £1,250 on top of the current year, depending on the exact historic allowance amounts. It's a quick form on gov.uk, and once it's approved it just renews itself automatically every year until someone cancels it or your circumstances change.

Not sure if it's worth it for you? Our Marriage Allowance Calculator will tell you in about ten seconds.