The HMRC has said people should apply for a benefit which can send the personal tax allowance of one worker in a couple to £13,830. The lowest level of personal tax threshold has been frozen since 2021 at £12.570.

This has come under fire for causing ‘fiscal drag’, meaning some of the poorest workers in the UK are paying more and more tax as inflation causes pay to rise, while the threshold stays the same. The HMRC has said couples where one doesn’t work can benefit from a rule - which has also been backed by personal finance TV expert Martin Lewis.

HM Revenue and Customs (HMRC) has previously urged people to take advantage of the offer whereby one person in a marriage can transfer their allowance to the other person.T he HMRC has added that individuals have the option to backdate their claim for the previous 4 tax years. meaning people can get a lump sum of more than £1,000.

The HMRC has said: “Marriage Allowance keeps money in your pocket by reducing the amount of tax you and your spouse pay by up to £252 a year. You can check your eligibility and apply on GOV.UK. Search ‘Marriage Allowance’ to find out more.”

“To benefit from the tax relief, one partner must have income less than the Personal Allowance of £12,570, and the higher earning partner’s income must be between £12,571 and £50,270 (£43,662 in Scotland).”

Mr Lewis has previously explained that couples can access financial help - and enjoy a significant tax break which will be backdated. The personal finance expert explained on his ITV show how married couples can benefit from the scheme if one partner isn’t working. Mr Lewis stated it effectively delivers a £1,260 tax saving for married couples - noting that it applies ‘provided one of you is aged under 90’.

And in a new post on X today, the show highlighted one couple who had benefited - and got a nice lump sum. They said: “We were watching the show and we heard Martin talking about transferring the spouse’s tax allowance.

“I had retired on medical grounds so I was not paying tax and he said that it is possible to transfer a non- taxpaying spouse’s tax allowance to their partner. Following the show, I went on to the gov.uk website and was surprised how easy it was to complete the forms. We are benefiting from about £250 a year in tax allowance. I was able to claim, I think it was about 4 years of back tax, which was about £1,000. And we used that £1,000 to have a rather nice holiday in Cornwall, particularly as it coincided with Hillary recovering from her chemo. If you can save a few pounds here and a few pounds there, it’s money in the pocket.”

Around 2.1 million people are failing to claim the funds - and those who haven’t previously done so could receive £1,260 as a lump sum - backdated for four years plus the current year. One partner must be a non-taxpayer, allowing them to transfer the portion of their personal allowance they’re not using. He stated: “Imagine we have a couple here. The crucial part of this. One of you needs to be a non-taxpayer, so you are not earning your full personal allowance you can earn before you start paying tax on it.”

If somebody isn’t paying income tax, he explained that would qualify them as a non-taxpayer for this relief. The other partner must be paying no more than the 20 per cent tax rate.

He stated: “Clearly you have to be married or civil partners. Then what happens is this, each of you have your £12,570 personal allowance. That’s the amount you can earn that you don’t pay tax on each year.

“So the non-taxpayer can apply to Gov.uk to move 10% of their tax-free allowance across to the basic rate taxpayer.”

He clarified that this arrangement would grant the non-taxpayer an allowance of £11,310 whilst their partner would receive a combined allowance of £13,830.

“Now that 10% extra tax-free allowance they have, remember they would have paid tax on it at 20%, so the gain there is £252 a year, and that’s what moving across works, and in virtually every circumstance, even if the person here earned a little bit above that threshold where they might pay a little bit of tax, but as long as the person on this side is earning over £13,830, you’re always going to be net up if there’s a non-taxpayer and a taxpayer.”

“The way it works for the current year your tax code is changed, for past years they send you a check or they send you a bank transfer. So the marriage tax allowance is absolutely crucial to do.”

Tax year // How much you could get

2026/27 £252

2025/26 £252

2024/25 £252

2023/24 £252

2022/23 £252

In Scotland, couples can benefit from Marriage Allowance if the partner with the higher income pays income tax at the starter, basic rate or intermediate rate – which typically means their income is between £12,571 and £43,662.

You can apply for marriage tax allowance here.