Marriage Allowance Calculator

What is the UK Marriage Allowance?

Marriage Allowance lets a non-tax-paying spouse or civil partner transfer £1,260 of their unused Personal Allowance to a basic-rate-paying partner. The receiving partner gets a tax cut worth up to £252 a year (£1,260 × 20%). It is one of the simplest, most overlooked tax breaks in the UK system. HMRC's own figures suggest more than one million eligible couples do not claim it.

The reason is not complexity. The claim takes about ten minutes on gov.uk/marriage-allowance and HMRC pays out within roughly six weeks. The reason is that the UK tax system relies on citizens claiming benefits proactively rather than applying them automatically. That bias rewards the well-informed and penalises the time-poor, which is exactly the wrong way round.

Who qualifies for Marriage Allowance?

Four conditions have to be met at the same time:

• You are married or in a civil partnership. Cohabiting couples do not qualify, no matter how long they have lived together.
• The lower earner's income is below £12,570, the Personal Allowance. Income includes earnings, taxable pensions, and most other taxable income before tax.
• The higher earner is a basic-rate taxpayer, meaning their income is between £12,571 and £50,270. If they pay higher or additional-rate tax, the allowance cannot be claimed.
• You were both born after 6 April 1935. Couples with a partner born before that date get the older and more generous Married Couple's Allowance instead.

Use this calculator to check both incomes against the thresholds. If you are close to a boundary, also check your gross figure on the take-home pay calculator so you know which side of the line you sit on.

Backdating: claim up to four previous tax years

If you were eligible in earlier years but never claimed, you can backdate the Marriage Allowance up to four tax years. Combined with the current year, that is up to five years of £252, or £1,260 paid as a lump sum. HMRC issues backdated amounts either as a tax refund cheque, a bank transfer, or by adjusting the receiving partner's tax code, depending on the year and circumstances.

Both partners need to have met the eligibility tests in each year you backdate. If the lower earner had a year where they earned over £12,570, that year drops out of the claim, but the other years are unaffected. Do not pay a "tax reclaim agent" to do this for you. Some firms take 30 to 50% of the refund for filling in a form you can file yourself for free.

Worked example

The numbers stay the same whether the lower earner is a stay-at-home parent, a student, a part-time worker on low hours, someone on a career break, or a retiree drawing only a small pension. The only thing that matters is that they sit below the £12,570 Personal Allowance and the other partner sits in the basic-rate band.

Edge cases: divorce, mid-year income changes, and pension contributions

Divorce or separation. The transfer stays in place for the rest of the tax year in which you separate, then cancels automatically from the next 6 April. Either partner can cancel earlier by contacting HMRC. There is no need to repay anything if you were genuinely eligible at the start of the year.

Income changes mid-year. If the lower earner picks up extra work and goes above £12,570, the transfer may end up costing the couple money because the lower earner is now paying tax on income that would otherwise have been covered by the £1,260 they gave away. HMRC normally squares this up through self-assessment or a tax code adjustment, but if you can see the year heading that way, cancel the transfer.

Pension contributions matter. Personal pension contributions reduce your taxable income for higher-rate purposes. A partner earning £52,000 who pays £2,000 into a SIPP is treated as having a taxable income of £50,000, which puts them back inside the basic-rate band and back inside Marriage Allowance eligibility. This is one of several reasons SIPP and workplace pension contributions are worth more than the headline 20% relief suggests.

Marriage Allowance vs Married Couple's Allowance

These two sound identical and are constantly confused, but they are different reliefs for different generations.

• Marriage Allowance (this calculator) is the modern version. Both partners must be born after 6 April 1935. The benefit is up to £252 a year.
• Married Couple's Allowance applies when at least one partner was born before 6 April 1935. It is worth more (between £427 and £1,108 a year for 2026-27) and is income-tested. If you qualify for this one, you cannot also claim Marriage Allowance.

For everyone under the age of about 91, Marriage Allowance is the only one that matters. It is also the one HMRC heavily under-promotes, which is why the take-up rate is so poor.

Frequently asked questions