What is the Marriage Allowance?
Marriage Allowance lets a spouse or civil partner earning below the personal allowance transfer 10% of it — £1,260 — to a partner who is a basic rate taxpayer. The recipient saves 20% of that, worth £252 a year.
It can be backdated four tax years, so a first claim can be worth over £1,250. Millions of eligible couples never claim it.
Formula & worked example
Saving = £1,260 × 20% = £252 per year
Backdated up to 4 previous tax years
Worked example: one partner earns £8,000 (below the allowance) and the other £35,000 (basic rate). Transferring £1,260 saves the higher earner £252, while the lower earner still pays no tax. Backdating four years adds £1,008, bringing the total claim to about £1,260.
How to use this marriage allowance calculator
- Enter both incomes — the lower must be below the personal allowance.
- The higher earner must be a basic rate taxpayer (below £50,270).
- Set years to backdate — up to four previous tax years are claimable.
- Apply directly through gov.uk; never pay an agency a percentage to do it.
Smart tips
- Apply on gov.uk for free. Claims agencies charge large fees for a form that takes ten minutes.
- Backdating four years makes a first claim worth over £1,200 — well worth the time.
- Once applied, it renews automatically each year until you cancel or circumstances change.
- If the higher earner becomes a higher rate taxpayer, eligibility ends and you must notify HMRC.
- Married Couple's Allowance is a different, more generous relief for couples where one partner was born before 6 April 1935.
Frequently asked questions
Who is eligible for Marriage Allowance?
Married couples or civil partners where one earns below the personal allowance and the other is a basic rate taxpayer.
How much is Marriage Allowance worth?
£252 a year, and up to four previous years can be backdated, making a first claim worth over £1,250.
How do I apply?
Free through gov.uk. The lower earner makes the application, and it renews automatically thereafter.
Can I claim if my partner is a higher rate taxpayer?
No. The receiving partner must pay tax at the basic rate, meaning income below £50,270.
Want the theory behind the numbers? Browse the Money Blog for worked guides.
Written by Gurjeet Singh, Sharpen Solutions. Last reviewed 15 Oct 2026. Sources: GOV.UK — Marriage Allowance: transferable amount. How we check these numbers.