Marriage Allowance is one of the simplest tax reliefs going, and one of the most often missed. If you're married or in a civil partnership and one of you earns less than the tax-free Personal Allowance, you could cut your household tax bill by up to £252 a year, with a backdated lump sum on top.
It lets the lower earner transfer part of their unused Personal Allowance to the higher earner. The Personal Allowance is frozen at £12,570 for 2025/26, so a lot of couples qualify and never realise it.
This guide explains how the relief works, who's eligible, exactly how much you can save, how to backdate up to four years, and the scenarios we see most often with self-employed and ecommerce clients. It's written for business owners, but it works just as well if you're employed.
<a id="what-is-marriage-allowance"></a>What is Marriage Allowance and how does it work?
Marriage Allowance lets the lower earner in a married couple or civil partnership transfer a fixed slice of their Personal Allowance to their partner.
The Personal Allowance is the amount you can earn before you pay Income Tax. For 2025/26 it's £12,570. Marriage Allowance lets the lower earner hand over £1,260 of that to the higher earner.
That £1,260 then reduces the higher earner's tax bill by £252, which is 20% of £1,260 at the basic rate. The catch is that the lower earner must not actually need the allowance they're giving up. If they already earn more than £12,570, there's nothing spare to transfer.
It's an ongoing relief. Once it's in place, it renews automatically each tax year until one of you cancels it or your circumstances change.
<a id="who-qualifies"></a>Who qualifies in 2025/26?
The rules are short, but it's worth checking each one. Couples who look eligible sometimes aren't, and couples who assume they don't qualify sometimes do.
The lower earner's income must be at or below £12,570 for 2025/26. That means total taxable income across everything: employment, self-employment profit, pension, rental income, savings interest and dividends combined. It doesn't matter whether the money comes from a job, a Shopify store or a buy-to-let.
The higher earner must be a basic rate taxpayer. Their income needs to sit in the basic rate band, broadly £12,571 to £50,270 for 2025/26 in England, Wales and Northern Ireland. Higher rate (40%) and additional rate (45%) taxpayers don't qualify.
You must be married or in a civil partnership. Living together, however long, doesn't count. This is the single most common misunderstanding we hear.
Scotland is different. Scottish taxpayers have their own Income Tax rates and bands, so the basic rate test isn't identical. If either of you is a Scottish taxpayer, check your position before assuming the rUK thresholds apply.
Pensioners can qualify too, which is easy to overlook if a couple's main income is a private or state pension below the Personal Allowance.
<a id="how-much-can-you-save"></a>How much can you actually save?
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The maximum saving is £252 per tax year for 2025/26. That's the 20% basic rate applied to the £1,260 transfer.
It doesn't sound huge on its own, but it stacks up once you backdate. A couple who've been eligible for several years and never claimed can recover a meaningful lump sum, and it costs nothing to claim.
Where the saving lands depends on how the higher earner pays tax. If they're on PAYE, their tax code is adjusted and they see the benefit spread across their pay over the year. If they file a Self Assessment return, the credit reduces the tax due, so it comes off the January bill.
If you want a quick sense of where each partner sits against the thresholds, our income tax calculator will show your tax-free allowance and which band you fall into.
<a id="how-to-claim"></a>How do you check eligibility and claim?
The process is free, online and takes about five minutes. A few points matter.
The lower earner makes the claim. The transfer comes from their allowance, so they're the one who applies. You'll need both partners' National Insurance numbers and a way to prove identity (such as a recent payslip or P60).
You apply through the official HMRC service at gov.uk/marriage-allowance. HMRC confirms the outcome shortly after you submit.
If the higher earner files a Self Assessment return, the claim can also be handled through the return. If we prepare your return, we check whether the allowance is already in place before we file.
Before you apply, it's worth confirming three things:
- The lower earner's total income, including any side income from an online shop, rent or interest, is genuinely at or below £12,570 for 2025/26.
- The higher earner is a basic rate taxpayer, not a higher rate taxpayer.
- Whether backdating applies, so you claim the earlier years in one go.
<a id="backdating"></a>How far back can you backdate a claim?
You can backdate a Marriage Allowance claim by up to four tax years, as long as you were eligible in each of those years. Claiming during the 2025/26 tax year, you can go back to 2021/22.
HMRC pays the backdated amount as a lump sum, either as a repayment or by adjusting the higher earner's tax code so they take home more before tax in the current year.
Illustrative example. Sam and Alex married in 2021. Sam works part-time and has stayed under the Personal Allowance every year since. Alex is a basic rate taxpayer. They never claimed. Backdating to 2021/22 plus the current year, that's £252 for each eligible year. They recover the earlier years as a lump sum and the current year through Alex's tax code.
Income that swings year to year is exactly where backdating earns its keep. If the lower earner had a quiet year and dropped below £12,570, they may have been eligible for that year even if they aren't now. It's worth checking each year on its own rather than assuming this year's position held throughout.
<a id="ecommerce-self-employed"></a>How does it apply to ecommerce and self-employed people?
If you run an online business or work for yourself, a few patterns come up again and again.
Variable-income sellers. Amazon, Etsy and Shopify income can move a lot from one year to the next. A seller who had a slow year under £12,570 might be eligible for that year, even if they earned more before or after. Check each year separately. For sector-specific support, see our ecommerce accounting page.
Sole traders with a working spouse. This is the textbook case. Say you earn £10,000 from an online store and your spouse earns £35,000 from a job. You transfer £1,260 of your unused allowance and your spouse saves £252. We cover this routinely as part of Self Assessment work for sole traders.
Limited company directors on a low salary plus dividends. Many directors take a small salary and top up with dividends. Whether you qualify depends on your total taxable income, and dividends count towards that total. The dividend allowance for 2025/26 is £500, so only the first £500 of dividends is tax-free, and the rest still counts as income for the eligibility test. Work out salary plus dividends carefully before assuming the allowance is unused.
Check both directions. Even if the director's own income is too high, their partner might be the lower earner. Test each partner against the thresholds, not just one.
The habit worth building is a quick income check for both partners at the start of each tax year review. For the couples who qualify, it's one of the fastest wins available.
<a id="vs-married-couples"></a>Marriage Allowance vs Married Couple's Allowance
These are two separate reliefs, and they get mixed up constantly.
Marriage Allowance is the one this guide covers. It's open to married couples and civil partners who meet the income conditions, and it saves up to £252 a year for 2025/26 through a Personal Allowance transfer.
Married Couple's Allowance is only for couples where at least one partner was born before 6 April 1935. It works as a reduction to your tax bill rather than a transfer of allowance, and for 2025/26 it cuts the bill by between £436 and £1,127, depending on income.
You can't receive both at the same time. If one of you was born before 6 April 1935, check which relief leaves you better off before you apply.
<a id="circumstances-change"></a>What happens when your circumstances change?
Marriage Allowance renews automatically once it's in place. That's handy while you stay eligible, but it means you need to cancel it when it no longer fits.
Cancel the claim if:
- You separate or divorce, or dissolve the civil partnership.
- The lower earner's income rises above £12,570.
- The higher earner becomes a higher rate taxpayer.
- A partner dies (HMRC handles bereavement cases separately).
The lower earner cancels through their HMRC online account. HMRC then adjusts both tax codes, usually from the start of the next tax year.
If your circumstances change and the claim isn't cancelled in time, you can end up with tax to repay, which HMRC will usually collect the following year. A quick annual check is the simplest way to avoid that.
<a id="faqs"></a>FAQs
Who qualifies for Marriage Allowance in 2025/26? You qualify if you're married or in a civil partnership, the lower earner has total taxable income at or below £12,570, and the higher earner is a basic rate taxpayer (broadly £12,571 to £50,270 in England, Wales and Northern Ireland). Scottish taxpayers should check their own bands.
Can Marriage Allowance be backdated? Yes, up to four previous tax years where you were eligible. Claiming during 2025/26, you can go back to 2021/22. HMRC pays the backdated amount as a lump sum or applies it through the higher earner's tax code.
Does Marriage Allowance affect a Self Assessment return? Yes. If the higher earner files a return, the credit reduces the tax due. If we prepare the return, we check whether the claim is already registered, and if not, it can be registered through the return.
Does it apply to civil partners? Yes. The same rules and the same £252 maximum saving apply to civil partners as to married couples for 2025/26.
What if income includes dividends or savings interest? Both count towards total taxable income for the eligibility test. Add all income together before deciding whether the lower earner is at or below £12,570. For company directors taking dividends, the dividend allowance for 2025/26 is £500, so check salary plus dividends carefully.
Can my accountant claim it for me? The claim has to be made by the lower-earning partner, because it's their Personal Allowance being transferred. We can confirm your eligibility in advance, talk you through the application, and make sure the claim is reflected correctly in your Self Assessment return.
What if my circumstances change after I claim? The claim renews each year automatically, so review it if anyone's income changes a lot. If the lower earner goes above £12,570 or the higher earner becomes a higher rate taxpayer, cancel the allowance online to avoid an underpayment the following year.
Talk to Zmartly about your Marriage Allowance
Not sure whether you or your spouse qualify, or whether there's a backdated refund waiting? Book a free 20-minute call with a Zmartly accountant and we'll check both partners' positions and the four backdating years for you. Get in touch with Zmartly.
<a id="sources"></a>Sources
- HMRC, Marriage Allowance: how it works: https://www.gov.uk/marriage-allowance
- HMRC, Married Couple's Allowance: what you'll get: https://www.gov.uk/married-couples-allowance/what-youll-get
- HMRC, Income Tax rates and Personal Allowances: https://www.gov.uk/income-tax-rates
- HMRC, Income Tax rates and allowances (current and past): https://www.gov.uk/government/publications/rates-and-allowances-income-tax/income-tax-rates-and-allowances-current-and-past
- HMRC, Tax on dividends: https://www.gov.uk/tax-on-dividends
- HMRC, Scottish Income Tax: https://www.gov.uk/scottish-income-tax
