Pensioners could face unexpected tax bill due to 'marriage allowance mayhem'

Pensioners who have shared part of their £12,570 personal allowance with their spouse through the marriage allowance scheme could face a surprise bill in 2024-25.

This is due to a combination of frozen personal allowance thresholds and a big increase to the state pension – due in April 2024 and worth 8.5%.

Former pensions minister Sir Steve Webb has raised concerns this could lead to ‘marriage allowance mayhem’. 

Here, Which? explains who is likely to be impacted, what marriage allowance is, and how to avoid a tax bill.

How does marriage allowance work?

Marriage allowance is a tax perk available to couples who are married or in a civil partnership, where one low earner can transfer £1,260 (10%) of their personal allowance to their partner.

The higher-earning spouse, who must be a basic-rate taxpayer, will then receive a tax credit equivalent to the amount of personal allowance that has been transferred to them. 

This is deducted from the amount of tax they would usually have to pay – usually 20% tax on £1,260, which equates to a saving of £252 per year.

Once you’ve used the marriage allowance, the transfer carries on every year until it is revoked. You can also backdate it for up to four tax years, providing you were eligible to use it. 

• Find out more:marriage allowance explained 

Why is this a problem?

Mr Webb warns that until now, a spouse receiving the state pension could freely hand over 10% of their allowance at no cost to themselves because their taxable income was below 90% of the full allowance.

In the Autumn Statement, Jeremy Hunt confirmed the state pension would increase by 8.5% in April, meaning the full rate of the new state pension will be worth £11,502.40 per year. 

But there was no mention of personal personal tax thresholds, which are due to remain frozen until 2028. This means the personal allowance, which is what you can earn before paying tax, will remain at £12,570 or £11,310 for a partner who has shared 10% of their allowance.

The freeze means that those who have shared their allowance (typically women) will now go over their 90% threshold – using 91.5% of their personal allowance. 

If they take no action they will have a small tax liability as their state pension will take up £11,502.40, but their personal allowance will remain at £11,310.

• Find out more: Autumn Statement 2023: what it means for your money 

Who's impacted?

Webb said in most cases, the husband will be the taxpayer and the wife will have the lower income and be a non-taxpayer. 

The latest government figures suggest that 2.1 million couples benefitted from marriage allowance in the 2020-21 tax year, and one in three of these are estimated to be pensioner couples.

• Find out more:35 ways to save on tax

Should you stop your marriage allowance?

Couples will have two options.

You can carry on with the marriage allowance, leaving one partner to get a small tax bill every year. This will need to be paid by self-assessment if you have no other income. 

This tax will usually be collected using a Simple Assessment process via a tax demand in the post at the end of the financial year. 

Or you could stop the marriage allowance, which will increase one partner's tax bill and could potentially leave you as a couple worse off overall.

Pension tax warning

And it’s not just those who have used marriage allowance who may face a tax bill next year due to the state pension increase.

In September, we reported on concerns that over half a million more pensioners could have to start paying income if the state pension were to rise by 8.5% and the personal allowance remained frozen.

Currently, the 2023-24 full rate of the new state pension takes up all but £1,970 of the personal tax allowance (£12,570 allowance minus £10,600 pension). But in 2024-25 it will take up all but £1,068 of your personal tax allowance (£12,570 allowance minus £11,502 pension). This means even those with a modest private income will be tipped into paying the basic rate of tax at 20%.

How do you pay tax on your pension?

Whether the state pension is your only income or you're still in work, this is how your tax bill will need to be paid:

If you get a personal pension and the state pension

Your pension provider will normally take off any tax you owe before it pays you. It will also take off any tax you owe on your state pension.

If you have more than one personal pension, HMRC will ask one of your providers to take off the tax due on your state pension. 

At the end of the year, you'll get a P60 from your provider showing how much tax you've paid. 

If the state pension is your only income

In this case, you're responsible for paying any tax you owe and will need to fill in a self-assessment tax return.

If you started getting your pension on or after 6 April 2016, don’t send a tax return. HMRC will write to tell you what you owe and tell you what to pay. This is called a Simple Assessment tax bill. 

• Find out more:how to fill in a self-assessment tax return  

If you're still in work

Your current employer will take any tax due off your earnings and your state pension under PAYE.

If you're self-employed, you must fill in a self-assessment tax return at the end of the tax year, declaring your overall income. 

• Find out more: how to plan for retirement 

If you have other income 

You’re responsible for paying any tax you owe on income other than money from your pensions. For example, this could be money from investments, property or savings. 

• Find out more:tax on savings and investments