How to Cancel Marriage Tax Allowance: Online, Phone, or Post

You can cancel Marriage Allowance in two ways: online through your GOV.UK account, or by calling HMRC on 0300 200 3300. Either method takes only a few minutes if you have your National Insurance number and the date of the change to hand. What matters more than the method is the timing. If you’re cancelling because of a change in income, the transfer runs until 5 April and stops from the new tax year. If you’re cancelling because of divorce or dissolution, HMRC can backdate the cancellation to the start of the current tax year, which may leave the recipient owing tax.

Cancel Online Through GOV.UK

The quickest route is gov.uk/marriage-allowance/if-your-circumstances-change. HMRC will ask you to prove your identity using details it already holds, such as information from your tax records or payslips.¹

The service walks you through the reason for cancellation and confirms the change on screen. A follow-up message arrives by email or in your GOV.UK account. Ten minutes is usually enough if your details are ready.

Cancel by Phone or Post

To cancel by phone, call the HMRC Marriage Allowance helpline on 0300 200 3300. From outside the UK, use +44 135 535 9022. The line is open Monday to Friday, 8am to 6pm.¹ Have your National Insurance number, the reason for cancelling, and the relevant dates ready before you dial.

Post is the slowest option. The HMRC Marriage Allowance transfer form asks for the full name, National Insurance number, date of birth, and address of both partners, plus the date of your marriage or civil partnership.² Expect a longer wait before your tax code updates if you go this way.

What You Need Before You Start

Gather these before contacting HMRC by any method:

National Insurance numbers for both you and your partner²
The date of your marriage or civil partnership, matching what HMRC has on file
The reason for cancelling: change of income, divorce, dissolution, or bereavement
The date of the change, such as when your decree absolute was granted or your income changed

The dates matter because they decide when the cancellation takes effect and whether HMRC backdates any adjustments.

When the Cancellation Takes Effect

If you’re cancelling because of a change in income, the allowance keeps running until 5 April, and the cancellation takes effect from 6 April.¹ You keep the benefit for the rest of the current tax year, so there’s no rush to cancel mid-year on income grounds alone.

If your relationship has ended through divorce or dissolution, the cancellation may be backdated to 6 April at the start of that tax year.¹ Backdating means the recipient loses the tax reduction for the whole year and may owe extra tax. The transferor’s full Personal Allowance is restored from the same date. If you’re the recipient and your ex-partner has cancelled, check that your tax code has been adjusted and budget for a possible underpayment.

If Your Partner Dies

You do not need to cancel Marriage Allowance yourself after a bereavement. If you transferred part of your Personal Allowance to your partner and they die, their estate is treated as having the increased allowance, and yours returns to the normal amount.¹

If your partner transferred their allowance to you and then died, you keep the higher Personal Allowance until 5 April. Their estate is treated as having the reduced amount.¹ In either case the allowance stops automatically from the next tax year, but it’s worth confirming with HMRC that your tax code has been corrected.

How Your Tax Code and Take-Home Pay Change

While Marriage Allowance is active, the recipient’s tax code ends in “M” and the transferor’s ends in “N.”³ After cancellation, both codes revert to reflect the standard Personal Allowance of £12,570.⁴

For the recipient, losing the extra £1,260 of allowance at the 20% basic rate works out to roughly £21 more tax a month, or £252 across the year. The transferor gets their full Personal Allowance back, which can reduce their tax if their income has risen above £12,570 since the original claim.

Tax code updates usually appear within a few weeks. If your employer is still using the old code after two months, contact HMRC to chase it.

Why You Might Need to Cancel

Marriage Allowance keeps running automatically every tax year until someone cancels it. If your circumstances change and neither of you notices, the transfer continues whether it still benefits you or not.

The most common reason to cancel is a change in income. Marriage Allowance only works when the transferor earns below the £12,570 Personal Allowance and the recipient earns between £12,571 and £50,270, keeping them in the basic rate band.⁵ If the recipient’s income crosses into the higher rate, they no longer qualify. If the transferor starts earning above £12,570, the transfer cuts their own Personal Allowance unnecessarily, and the couple can end up worse off overall.

Scotland has a lower ceiling. Scottish taxpayers qualify only if they pay tax at the starter, basic, or intermediate rate, usually meaning income between £12,571 and £43,662.⁵

Divorce or dissolution of a civil partnership also ends eligibility, as does separating and starting to live with a new partner.¹

Backdated Refunds Are Not Clawed Back

Marriage Allowance can be backdated up to four previous tax years when you first apply, currently reaching back to 2021/22.⁵ If you claimed backdated years and are now cancelling, those earlier refunds are not reclaimed. Cancellation only affects the current and future tax years.

The reverse also holds. If you never claimed but were eligible in past years, you can still apply for those years even if you’re no longer eligible going forward. A change in income or a divorce now doesn’t wipe out eligibility you had in 2022 or 2023, so it’s worth checking before you assume the benefit is entirely gone.

1
GOV.UK. Marriage Allowance – If Your Circumstances Change
2
HM Revenue and Customs. Marriage Allowance Transfer
3
GOV.UK. Marriage Allowance – How to Apply
4
GOV.UK. Income Tax Rates and Personal Allowances
5
GOV.UK. Marriage Allowance – How It Works