The marriage allowance is available to married couples and those in a civil partnership where a spouse or civil partner does not pay tax or does not pay tax above the basic rate threshold for Income Tax (i.e., one of the couples must currently earn less than the £12,570 personal allowance for 2023-24).
The allowance works by permitting the lower earning partner to transfer up to £1,260 of their personal tax-free allowance to their spouse or civil partner. The marriage allowance can only be used when the recipient of the transfer (the higher earning partner) does not pay more than the basic 20% rate of Income Tax. This would usually mean that their income is between £12,571 to £50,270 for the 2023-24 tax year. The limits for those living in Scotland may vary slightly from these figures.
Claiming the allowance could result in a saving of up to £252 for the recipient (20% of £1,260), or £21 a month for the current tax year. In fact, even if a spouse or civil partner has died since 5 April 2018, the surviving person can still claim the allowance (if they qualify) by contacting HMRC’s Income Tax helpline.
If you meet the eligibility requirements and have not yet claimed the allowance, you can backdate your claim to 6 April 2017. This could result in a total tax refund of up to £1,242 if you can claim for 2019-20, 2020-21, 2021-22, 2022-23 as well as the current 2023-24 tax year. Even if you are no longer eligible, but you would have been in all or any of the preceding years, you can still claim your entitlement.