Marriage Allowance Backdating: The 2021/22 Tax Year Drops Off After April 5 — Claim Now or Lose £1,220

Marriage Allowance lets the lower earner in a married couple or civil partnership transfer £1,260 of their Personal Allowance to the higher earner. The Personal Allowance — currently £12,570 — is the amount you earn before paying income tax.

The transfer reduces the higher earner's tax bill by up to £252 for the 2025/26 tax year. Not a fortune. But it compounds when you backdate.

To qualify, the lower earner must normally have income below their Personal Allowance (£12,570), and the higher earner must be a basic-rate taxpayer — income between £12,571 and £50,270 in England, Wales, and Northern Ireland. In Scotland, the higher earner must pay the starter, basic, or intermediate rate, meaning income between £12,571 and £43,662.

You must be married or in a civil partnership. Cohabiting couples don't qualify — regardless of how long you've lived together.

For the full picture of UK income tax bands and rates for 2025/26, including how the personal allowance interacts with other allowances, see our tax hub.

Here's what you can claim right now if you backdate to every eligible year:

2021/22: £230 (Personal Allowance transfer of £1,260 × 20% = £252, but the rate was slightly lower at £1,150 transfer = £230)

2022/23: £242 (transfer of £1,260 × 20%, minus the transitional adjustment)

2023/24: £252 (£1,260 × 20%)

2024/25: £252 (£1,260 × 20%)

2025/26: £252 (£1,260 × 20%)

Total if you claim now and backdate to 2021/22: up to £1,220. After 5 April 2026, you lose the 2021/22 year entirely. The maximum drops to around £998.

That £230 gap is the price of procrastination. It will never be recoverable.

HMRC's own estimates suggest around 2 million eligible couples haven't claimed. The typical non-claimant falls into one of three groups.

Retired couples where one partner has a small pension. State pension alone is around £11,500 for the full new state pension — below the £12,570 Personal Allowance. If the other partner has workplace pension income in the basic-rate band, they qualify. Many retired couples have been eligible since Marriage Allowance launched in 2015 and have never claimed a penny.

Single-income households with children. One parent earning £30,000–£50,000 while the other stays home or works part-time below the Personal Allowance. These families often focus on Child Benefit clawback calculations and overlook Marriage Allowance entirely. They're often the same households that should be maximising their ISA allowances before the same April 5 deadline.

Couples where one partner is self-employed with fluctuating income. If one partner had a bad year and earned below £12,570, that year qualifies — even if they earned more in other years. You can backdate selectively, claiming only for the years you were eligible.

Couples where one partner recently retired. The state pension alone is below the Personal Allowance threshold. If one partner has retired and the other still works at a basic-rate salary, Marriage Allowance applies from the tax year the retirement began. Many couples miss this because they associate the allowance with younger families, not retirees.

The process is straightforward. The lower earner applies online through GOV.UK. You'll need your National Insurance number and your partner's National Insurance number.

If you're registered for Self Assessment, fill in the Marriage Allowance section on your tax return instead. The person transferring the allowance should file their return at least three days before the person receiving it.

To backdate, select the option to claim for previous tax years during the online application. HMRC will calculate the refund and either adjust your partner's tax code or send a cheque.

Tax code changes can take up to two months. Your code will end in 'M' if you're receiving the allowance, or 'N' if you're transferring it. Once set up, the transfer renews automatically each year until you cancel it.

One detail people miss: if your partner died after 5 April 2021, you can still claim. Phone the Income Tax helpline rather than applying online.

Marriage Allowance isn't universally beneficial. If the lower earner has income just below the Personal Allowance — say, £12,000 — transferring £1,260 creates a taxable gap of £690 on their side. They'd pay tax on £690 at 20% (£138), while their partner saves £252. Net benefit: £114, not £252.

If both partners earn above the Personal Allowance, you can't claim at all. And if the higher earner pays tax above the basic rate — income over £50,270 — they don't qualify either. Marriage Allowance is specifically for basic-rate taxpayer partners.

Couples born before 6 April 1935 should check Married Couple's Allowance instead, which can be more generous.

Marriage Allowance also interacts with other tax breaks. If you're close to the Personal Savings Allowance threshold, transferring part of your Personal Allowance could push the lower earner into a taxable position on savings interest.

For our broader guide to UK income tax rates and planning, including how Marriage Allowance fits alongside other allowances, see our tax hub. See our analysis on Marriage Allowance is worth £1,252 before April 5.

Today is 21 March 2026. You have 15 days until the 2021/22 tax year permanently exits the backdating window.

The online application takes roughly 15 minutes. The backdated refund arrives within weeks — either as a cheque or a tax code adjustment that reduces future PAYE deductions.

If you're eligible and you've been meaning to get around to it, this is the nudge. £230 isn't transformative, but it's £230 more than you'll have if you wait until 6 April.

While you're at it, check the other April 5 deadlines: your £3,000 CGT allowance and ISA allowance also expire the same day.

For couples already claiming Marriage Allowance going forward, check whether you've backdated fully. Many people set it up for the current year without realising they could have claimed for previous years too. The online portal shows which years are included in your claim — log in and verify.

This article is for informational purposes only and does not constitute financial advice. You should seek independent financial advice before making any investment decisions.