Marriage Allowance is about as close to free money as the UK tax system offers, a simple transfer that can save a couple £252 a year, backdatable for up to four years on top. HMRC estimates around two million eligible couples still haven't claimed it. If you're married or in a civil partnership and one of you earns less than the other, it's worth five minutes to check whether you qualify.
For how this fits into your wider take-home pay, see our take-home pay calculator.
Who Actually Qualifies
Three conditions all have to be true at the same time.
You must be married or in a civil partnership. Living together without being married or in a civil partnership doesn't qualify, regardless of how long you've been together or whether you have joint finances.
The lower-earning partner must have income below the Personal Allowance, currently £12,570. This doesn't mean no income at all, plenty of people qualify with a part-time job, a small pension, or savings interest that keeps them under the threshold.
The higher-earning partner must be a basic rate taxpayer, meaning their income falls between £12,571 and £50,270. If the higher earner is already in the higher or additional rate band, the claim is rejected outright, since the allowance is only designed to help basic rate taxpayers.
How Much You Actually Save
The lower earner transfers £1,260 of their unused Personal Allowance to their partner. Since the lower earner wasn't using that portion of their allowance anyway, it costs them nothing to give it away. The higher earner's tax bill drops by 20% of that amount, exactly £252 a year.
| Amount | |
|---|---|
| Personal Allowance transferred | £1,260 |
| Tax rate applied | 20% |
| Annual saving | £252 |
This shows up as a change to the higher earner's tax code, typically moving from the standard 1257L to 1383M, reflecting the extra £1,260 of tax-free allowance. The lower earner's own code changes too, to something like 1131N, reflecting the allowance they've given away. Both codes are covered in more detail in our tax codes explained guide.
Worth knowing: Our take-home pay calculator's Marriage Allowance dropdown, under Advanced Options, now factors the transfer directly into your figures. Select "Transferring" or "Receiving" to see your exact take-home pay with the allowance applied, rather than estimating the £252 by hand.
Claiming Is Simpler Than People Expect
The lower-earning partner makes the application, not the higher earner, which surprises some people. It's done directly through gov.uk, takes a few minutes, and needs both partners' National Insurance numbers. Once approved, it typically continues automatically in future years without needing to reapply, though it's cancelled automatically if your circumstances change enough to break eligibility.
Backdating: The Part Most People Miss
Claims can be backdated up to four tax years, and this is where the real money often sits for couples who've been eligible for years without realising it. At present, that means you can backdate as far as the 2022/23 tax year, worth up to £252 for that year alone, plus £252 for each subsequent year you were eligible, plus the current year. A full four-year backdated claim combined with the current year can be worth over £1,000 in a single application.
The backdated amount arrives as a lump sum payment, separate from the ongoing saving, which then continues through the higher earner's adjusted tax code going forward.
Common Situations Where It Applies
A retired person living on the State Pension alone, with income just under £12,570, and a partner still working or drawing a private pension in the basic rate band is one of the most common and most frequently missed cases, since many pensioners don't think of Marriage Allowance as something aimed at them.
A stay-at-home parent with no income and a working partner is another straightforward case, as is anyone working part-time with earnings comfortably under the Personal Allowance while their partner works full-time in the basic rate band.
Ask your employer: Marriage Allowance is claimed directly through HMRC, not through payroll, so there's nothing to request from your employer specifically. If your tax code changes as a result of a successful claim, it's worth mentioning to payroll only if the change doesn't appear on your payslip within a reasonable time after applying.
When It Stops Making Sense
If the higher earner's income is close to the £50,270 higher rate threshold, it's worth checking whether pension contributions could keep them safely within the basic rate band, since crossing into higher rate voids the claim entirely. This is the same logic covered in our salary sacrifice explained guide, just applied to a different threshold.
If your circumstances change, the lower earner starts earning more, or you separate, it's worth actively cancelling the claim rather than leaving it running, since an invalid claim can result in HMRC reclaiming the saving later.