Marriage Allowance: what it is worth, and when it costs you

Marriage Allowance lets the lower earner in a married couple hand £1,260 of their personal allowance to the other, which cuts that partner's tax by up to £252 a year. You can backdate it four years, so a first claim can be worth up to £1,260. What almost nobody tells you is that it can also leave a couple worse off, and the two incomes that decide which is which are £11,310 and £13,830.

What you actually get

The £1,260 is not arbitrary. It is 10% of the £12,570 personal allowance, rounded up to the nearest ten pounds, which is why it is £1,260 and not £1,257. The relief on it is given at the basic rate, so 20% of £1,260 is £252, and that is the ceiling.

Two people can claim the same allowance and get different amounts, though, because both sides of the transfer matter. Your partner can only save tax they were actually going to pay, so the full £252 needs them earning at least £13,830. And you keep the whole benefit only if giving away £1,260 does not push you into paying tax yourself, which means earning no more than £11,310.

That is why gov.uk's own worked example nets £214 rather than £252: the person transferring earns £11,500, which is above the reduced allowance, so they pick up a small bill of their own. The headline figure and the example sit on the same page and are easy to confuse.

Who can claim

Three things must all be true.

You are married or in a civil partnership. Living together does not count, however long you have done it.

One of you earns under the personal allowance of £12,570, or pays no income tax at all.

The other pays basic-rate tax, which usually means income between £12,571 and £50,270 before the allowance is transferred.

Being retired does not disqualify you, and nor does living abroad as long as you still get a UK personal allowance. What does disqualify you is becoming a higher-rate taxpayer, and the test is applied at the end of the year, not the start. A bonus or a new job in March can make a claim you made in April invalid for the whole year.

Could it leave you worse off?

Yes, and this is the part worth reading twice. Most guides say the couple "might still benefit" and leave it there. The arithmetic is not complicated, so here it is in full: the lower earner's income down the side, the higher earner's across the top, and the net effect on the couple in the cells.

The couple's net position over a year, 2026/27 figures, rest of UK. A negative number means claiming costs you money, and the last column covers every income above it, because the saving is capped there. To see what either income looks like after tax, use the take-home pay calculator.

Read the shape rather than the individual cells. Everything in the top rows is safe: if the lower earner is on £11,310 or less, the worst that can happen is nothing. The losses appear in the bottom left, where the lower earner is above £11,310 and the partner is not earning enough to use the full transfer. On £11,970 and £12,870, for instance, the transfer costs £132 and gains £60, so the couple is £72 down.

So the two rules worth remembering are these. If the person giving the allowance away earns £11,310 or less, you cannot lose. If the person receiving it earns £13,830 or more, you get the full £252. It is only the narrow band between those two that needs any thought at all.

If you live in Scotland

Two differences, and the second is more interesting than the first.

The qualifying range is narrower. Your partner has to be paying the starter, basic or intermediate rate, which runs to £43,662rather than the £50,270 that applies in the rest of the UK. Someone earning £45,000 in Scotland pays the 42% higher rate and cannot claim, while the same salary in England qualifies comfortably.

But the relief is still worked out at the UK basic rate of 20%, whichever Scottish rate your partner actually pays. A Scottish starter-rate taxpayer pays 19% and gets relief at 20%; an intermediate-rate taxpayer pays 21% and gets relief at 20%. It cuts slightly in your favour at the bottom of the scale, which is worth knowing if you are close to the line on whether a claim is worth making.

Backdating four years

A first claim can cover this year and the four before it, back to 6 April 2022. The personal allowance has been £12,570 throughout that period, so every year is worth the same.

Two things about backdated years that are usually left out. They arrive as a refund to the higher earner rather than as a change to anyone's tax code, because HMRC does not re-code a closed year. And you have to be married or in a civil partnership at the moment you apply, so a couple who have since divorced or legally separated cannot claim for the years when they were together. Any guide that tells you to go back four years without mentioning that is giving half the picture to the people most likely to need the other half.

Applying is free and takes minutes. Firms that offer to do it for a cut of the refund are filling in the same form you can, and the postal form has a section specifically for nominating a paid agent, which is how they get paid out of your money.

How it reaches you

For the current year, HMRC changes your partner's tax code, which can take up to two months, and backdates the change to 6 April. You can check it has worked from the codes themselves: the code of the person receiving the allowance ends in M, and the code of the person giving it away ends in N.

If either of you fills in a Self Assessment return there are two rules that catch people out. The person transferring the allowance completes the Marriage Allowance section; the person receiving it leaves it blank. And if you both file, the transferor has to file at least three days before the recipient, or the claim does not attach properly.

Cancelling, and the trap

The claim renews automatically, every year, until somebody stops it, and it is up to you to tell HMRC if your circumstances change. So the common failure is not a rejected application, it is a claim that carries on quietly after the lower earner goes back to full-time work, building an underpayment that turns up later as a bill.

You must cancel if the relationship ends, if your income changes so that you no longer qualify, or if you simply want to stop. Cancelling online or by phone is the only way that works. Leaving the Marriage Allowance box blank on a tax return does not cancel anything, which is a reasonable thing to assume and wrong.

When the cancellation takes effect depends on why. If your income changed, the allowance runs to the end of the tax year. If the relationship ended, the cancellation can be backdated to the previous 6 April, and gov.uk warns that this may mean one of you has underpaid for the year. The two cases pull in opposite directions, which is worth knowing before you pick a date to tell them about.

If a partner dies

The allowance does not simply stop, and which way it falls depends on who died. Take a couple where £1,260 has been transferred, so one has an allowance of £11,310 and the other £13,830.

If the person receiving the allowance dies, their estate is treated as having the increased £13,830, and the survivor's allowance goes back to the normal £12,570.

If the person giving it away dies, the survivor keeps the higher £13,830 until 5 April and then returns to normal, and the estate is treated as having the reduced £11,310.

You can also still make a claim where a partner has died since 5 April 2022, which is the one case that has to be done by phone rather than online. If the person who died was the lower earner, it is whoever is managing their tax affairs who needs to make the call.

Married Couple's Allowance is a different thing

The names are nearly identical and the reliefs are not. Married Couple's Allowance is the older one, and you only qualify if one of you was born before 6 April 1935. You cannot hold both at once.

It works differently too. Rather than moving allowance between you, it gives a tax reduction worth 10% of an allowance figure, which for 2026/27 runs from £4,530 to £11,700 and tapers away as income rises above £39,200. On those allowances the reduction works out between £453 and £1,170 a year, which is several times what Marriage Allowance is worth.

So if either of you was born before April 1935, check that one first. Claiming the £252 when you could have had up to £1,170 is an expensive mistake, and because you cannot hold both, it is one you make by accident.

For what either income looks like after tax, and to see whether a change in earnings moves you out of qualifying, the take-home pay calculator runs both. The take-home pay guide and what your tax code means cover the codes this changes.

Common questions

How much is Marriage Allowance worth?

Up to £252 a year. You transfer £1,260 of your personal allowance to your partner, and because the relief is given at the basic rate of 20%, that is worth £252 off their tax bill. It is worth less than that if your partner earns under £13,830, because they cannot save tax they were never going to pay.

Can Marriage Allowance leave us worse off?

Yes, and it is the thing most guides skip. Giving away £1,260 of allowance drops yours to £11,310, so if you earn more than that you start paying tax you were not paying before. If your partner also earns too little to use the full transfer, the cost can exceed the gain. The rule is simple: you can only lose if the person transferring earns over £11,310 and the person receiving earns under £13,830.

Can I still backdate if we have since divorced?

No, and this contradicts a lot of what is written about backdating. HMRC requires you to be married or in a civil partnership at the moment you make the application, so a couple who have since divorced or legally separated cannot make a backdated claim for the years when they were together. If you are thinking about it and the relationship is ending, the order you do things in matters.

Which of us should apply?

The lower earner, always. They are the one giving away part of their allowance, so the application is made in their name and the postal form is signed by them. If neither of you has income beyond wages, it is simply whoever earns less.

What do tax codes M and N mean?

They are how you check it has worked. A tax code ending in M means that person is receiving the transferred allowance. A code ending in N means they are giving it away. If you applied and neither code has changed after a couple of months, something has gone wrong.

Do I have to apply again every year?

No, and that is a double-edged thing. The transfer renews automatically until you cancel it. HMRC does not re-test whether you still qualify, so if your income rises above the limit and you forget to cancel, you can build up an underpayment that gets asked for later.

Does Marriage Allowance work differently in Scotland?

The qualifying range is different and the relief is not. Your partner must be paying the starter, basic or intermediate rate, which usually means £12,571 to £43,662, against £50,270 in the rest of the UK. But the relief itself is still calculated at the UK basic rate of 20%, whichever Scottish rate they actually pay.

Is this article financial advice?

No. It sets out the published 2026/27 figures and rules and works out what they come to, with every figure produced by our own tested engine. The figures are estimates to help you plan, not financial advice. For your own position, check with HMRC.

About this article

Written by the calcd team. We build UK money calculators and explain the numbers behind them in plain English. The figures and rules come from gov.uk, with the mechanics of how the transfer is worked out and given from HMRC's PAYE Manual, and the Scottish bands from gov.uk on Scottish income tax. The net-benefit table is worked at page load by our own tested engine. The Married Couple's Allowance cash figures are 10% of HMRC's published 2026/27 allowances. Figures are estimates for the 2026/27 tax year, not financial advice. Last updated September 2026.