Check your eligibility and calculate the annual tax saving from transferring 10% of your Personal Allowance to your spouse.
This calculator provides estimates only. Marriage Allowance eligibility depends on individual circumstances. You can backdate claims for up to 4 previous tax years. Apply via gov.uk or contact HMRC.
Marriage Allowance is a tax benefit that allows one partner in a marriage or civil partnership to transfer 10% of their Personal Allowance to the other. For the 2026-27 tax year, this means transferring GBP 1,257 of tax-free allowance from the lower earner to the higher earner, resulting in a tax reduction of up to GBP 251.40 per year. This relief is specifically designed for couples where one partner earns less than the Personal Allowance of GBP 12,570 and the other is a basic rate taxpayer earning between GBP 12,571 and GBP 50,270. The lower earner does not use their full tax-free allowance anyway, so transferring part of it to their partner reduces the couple's overall tax bill. Despite being relatively simple to claim, HMRC estimates that millions of eligible couples have not yet applied, meaning many families are missing out on hundreds of pounds each year.
To check your Marriage Allowance eligibility: 1. Enter the lower earner's annual income. This is the income of the partner who earns less. They must earn less than the Personal Allowance of GBP 12,570 to be eligible to transfer their unused allowance. 2. Enter the higher earner's annual income. This is the income of the partner who will receive the transferred allowance. They must be a basic rate taxpayer with income between GBP 12,571 and GBP 50,270 for the transfer to benefit them. 3. Check your eligibility. The calculator will immediately tell you whether you qualify. If you do not qualify, it will explain why -- for example, if the lower earner earns too much or the higher earner is a higher rate taxpayer. 4. Review the savings. If eligible, you will see the annual tax saving, the amount of allowance being transferred, and the potential backdated claim for up to 4 previous tax years. 5. Consider backdating. If you have been eligible in previous years but have not claimed, you can backdate your claim. The total potential saving shown includes up to 4 years of backdated relief.
Marriage Allowance works by transferring 10% of the Personal Allowance from one partner to the other. For 2026-27, the Personal Allowance is GBP 12,570, so the transfer amount is GBP 1,257 (12,570 divided by 10, rounded down). The transferor's Personal Allowance reduces from GBP 12,570 to GBP 11,313. Since they earn less than GBP 12,570, this reduction has no tax impact on them -- they were not using that portion of their allowance anyway. The recipient's Personal Allowance increases from GBP 12,570 to GBP 13,827. They now pay tax on GBP 1,257 less of their income. At the basic rate of 20%, this saves GBP 251.40 per year (1,257 multiplied by 20%). The backdated claim calculation is straightforward: the annual saving multiplied by the number of years being backdated, up to a maximum of 4 previous tax years. The total potential saving is the current year saving plus the maximum backdated amount.
Marriage Allowance is one of the most under-claimed tax reliefs in the UK. HMRC has actively promoted it, but millions of eligible couples still have not applied. It is worth checking your eligibility even if you think you might not qualify. To apply, visit gov.uk/marriage-allowance and complete the online form. You will need your National Insurance number and your partner's. The process takes about 10 minutes. Once approved, HMRC adjusts the recipient's tax code automatically -- typically changing it from 1257L to 1382L. The relief continues automatically each tax year until one of you cancels it, you divorce or dissolve your civil partnership, or your circumstances change (for example, the lower earner starts earning above the Personal Allowance). You should review your eligibility each year, particularly if either partner's income has changed. Scottish taxpayers may have slightly different savings because Scotland has its own income tax rates. The starter rate of 19% means the saving is marginally lower at GBP 238.83, but the principle is the same. If the lower earner has any income from savings interest that falls within the Personal Savings Allowance, this can affect eligibility. The key test is whether their total income is below the Personal Allowance. Backdated claims are paid as a lump sum, while the ongoing annual benefit is applied through the PAYE tax code. Self-employed recipients will see the benefit reflected in their Self Assessment calculation.