Can I backdate Marriage Allowance?

Yes — by up to 4 tax years if you were eligible in those years. As of 2025/26 you can claim back to 2021/22, worth up to £1,260 in total.

What if my income changes mid-year?

Marriage Allowance is set at the start of the tax year and continues unless one partner cancels or HMRC removes it because the higher earner became a higher-rate taxpayer.

I see ads for 'tax refund' agents. Are they legit?

Many simply submit the free form on your behalf and charge 35–48% of the refund. HMRC has clamped down on the worst, but you can do it yourself in 5 minutes at gov.uk/marriage-allowance.

Eligibility · Marriage Allowance

Am I eligible for Marriage Allowance?

In short. If you're married or in a civil partnership, one of you earns under the Personal Allowance (£12,570) and the other is a basic-rate taxpayer (earning £12,571–£50,270), you can transfer £1,260 of unused allowance and save up to £252 a year in tax. Backdate up to 4 tax years.

Marriage Allowance lets the lower earner give some of their Personal Allowance to their spouse. It's free to apply and you can backdate by up to four tax years if you've been eligible the whole time.

Last reviewed: 26 May 2026

·Amount: Up to £252 of income-tax saving per tax year, plus back-claims of up to £1,260 (currently 2021/22 to 2024/25)

You likely qualify if…

You're married or in a civil partnership
One partner earns less than £12,570 (Personal Allowance)
The other partner is a basic-rate taxpayer (income £12,571 – £50,270)
Both partners were born on or after 6 April 1935 (older couples should claim Married Couple's Allowance instead)

You likely don't if…

You're not married or in a civil partnership (cohabiting doesn't count)
The higher-earning partner pays higher (40%) or additional (45%) rate tax
Both partners pay tax (no unused allowance to transfer)
Born before 6 April 1935 — Married Couple's Allowance is more generous

How to check and claim

01The HMRC eligibility checker is published at gov.uk/marriage-allowance
02Applications are made free of charge through the lower-earner's HMRC online account
03Third-party 'tax-back' agents typically charge a percentage of the refund (commonly 35–48%) for a service that is free at gov.uk/marriage-allowance

FAQ

Can I backdate Marriage Allowance?: Yes — by up to 4 tax years if you were eligible in those years. As of 2025/26 you can claim back to 2021/22, worth up to £1,260 in total.
What if my income changes mid-year?: Marriage Allowance is set at the start of the tax year and continues unless one partner cancels or HMRC removes it because the higher earner became a higher-rate taxpayer.
I see ads for 'tax refund' agents. Are they legit?: Many simply submit the free form on your behalf and charge 35–48% of the refund. HMRC has clamped down on the worst, but you can do it yourself in 5 minutes at gov.uk/marriage-allowance.

← All eligibility guides