Marriage allowance calculator
If one of you earns under the personal allowance and the other pays basic rate tax, you can move £1,260 of allowance between you. Many eligible couples never claim it.
How this is calculated
The lower earner transfers 10% of their personal allowance, £1,260, to the higher earner. That reduces the higher earner's taxable income by the same amount.
To qualify, the lower earner must have income below the personal allowance and the higher earner must be a basic rate taxpayer. If either condition fails, the claim is not available.
The saving is 20% of the transferred amount where the full amount is usable, so up to £252 a year.
The calculation also checks whether transferring would push the lower earner into paying tax themselves, and nets that off, since the point is the household saving rather than one person's bill.
Rates used · 2026/27
| Transferable amount | £1,260 |
| Maximum saving | £252 a year |
| Lower earner must be | below £12,570 |
| Higher earner must be | a basic rate taxpayer |
| Backdating | up to four tax years |
Last checked July 2026. Source: HMRC and gov.uk.
Worked example
One partner earning £8,000 has £4,570 of unused personal allowance. The other, on £35,000, is a basic rate taxpayer. Transferring £1,260 saves £252 a year. Claiming now and backdating four years would be worth up to £1,260 in one go.
Common questions
Who applies, the lower or higher earner?
The lower earner, because they are giving up part of their allowance. Apply free on gov.uk. Never use a paid claims company: they take a large cut of a refund you can get in ten minutes yourself.
Can I backdate?
Yes, up to four tax years, provided you were eligible in each. A first claim can therefore be worth over a thousand pounds.
Do we have to be married?
Yes. Marriage or civil partnership only. Living together does not qualify however long you have been together.
What if our circumstances change?
The claim continues automatically each year until you cancel it. If the lower earner starts earning above the allowance you should cancel, or you may end up owing tax.