If one partner earns under £12,570, you could transfer part of their unused personal allowance and cut your tax bill by up to £252 a year.

The Marriage Allowance applies to married couples and civil partners where one partner does not pay Income Tax, usually because their income is below the personal allowance. For the 2025–26 tax year, this means the lower-earning partner must earn less than £12,570.

The allowance means the lower-earning partner can transfer up to £1,260 of their unused personal allowance to their spouse or civil partner. This transfer is only permitted if the recipient is taxed at no more than the basic rate of Income Tax. This means the higher-earning partner must usually have an income between £12,571 and £50,270. For those living in Scotland, this generally applies where income does not exceed £43,662, which is the point at which the Scottish higher rate begins.

By using the allowance, up to £1,260 of unused personal allowance can be transferred, resulting in a tax saving of up to £252 per year for the higher-earning partner, calculated at 20% of the amount transferred.

If you meet the eligibility criteria and have not yet claimed the Marriage Allowance, you can backdate your claim for up to four previous tax years. At present, claims can be backdated to the 2021–22 tax year, meaning you may be able to claim for 2021–22, 2022–23, 2023–24, 2024–25 and the current 2025–26 tax year. This could result in a total tax saving of up to £1,260 across those years. Claims, including backdated claims and applications for the current year, can be made online via GOV.UK.