‘I’m a pensions and tax expert – watch out for six costly inheritance tax mistakes’

Inheritance tax (IHT) receipts are on the up and expected to rise further as more estates are dragged into HMRC’s net.

The government raked in £8.5 billion in inheritance tax receipts in 2025/26, with the Office for Budget Responsibility (OBR) forecasting the tax take will increase to almost £15 billion by 2030/31.

The watchdog says rising equity and house prices, frozen tax thresholds and the impact of policies announced in the 2024 Autumn Budget, namely unused pensions falling under the scope of IHT from April 2027, will, in part, cause the rise.

It means families may want to take steps to ensure their estate’s eventual IHT bill is as low as possible.

Unfortunately, many are still making six costly mistakes, says Clare Moffat, pensions and tax expert at retirement firm Royal London.

1. Not knowing the implications of cohabiting vs. marrying

For example, if you died and your estate was worth £300,000, there would be no IHT liability.

If you have a husband, wife or civil partner and die, any unused nil-rate band is passed to them, taking their threshold up to a potential £650,000.

If a property is being passed to children or grandchildren, there is an additional residence nil-rate band of £175,000 which can be transferred as well, potentially taking someone’s IHT-free allowance to £1 million.

However, these bands can only be transferred if you’re married or in a civil partnership, rather than if you’re cohabiting with someone.

Moffat says: “For me, this tops the list of mistakes that people can make if they’re in a long-term relationship.

“This means unmarried couples are potentially missing out on a total of £1 million in inheritance tax exemption.”

2. Not making the most of exemptions during your lifetime

There are a host of exemptions and allowances which mean you can gift money during your lifetime and it won’t fall into your estate for inheritance tax purposes.

For example, you get a £3,000 annual exemption each year. If you didn’t use it all in the previous tax year, you can carry the unused allowance forward to the next – but only for one tax year.

You can also donate £250 cash gifts to as many people as you want per tax year, unless you have used another allowance, like the annual exemption, on that person.

You can also gift an unlimited amount of money, so long as it is made out of ‘surplus income’ – that is money from pensions, rent or dividends – and it doesn’t reduce your standard of living.

Gifting money out of surplus income could become a useful way to reduce inheritance tax liabilities when unused pensions fall under the scope of IHT from April 2027.

Moffat says: “Gifting during life is not for everyone but for people who know that they will have more than enough to live on when they’re retired, the benefits are that it can help family when they need it most, be stopped at any time and you don’t need to worry about the seven-year rule.”

The seven-year rule means you can give away as much of your estate as you like during your lifetime, and if you live for another seven years the gifts won’t be subject to IHT.

3. Not keeping records

Keeping detailed records of any gifting throughout your lifetime will make it easier for the executors of your will to evidence it when they have to pay the IHT bill.

A lot of people don’t do this. Research from financial firm Canada Life found 54% of over 55s who had given a financial gift in the previous seven years had kept no record of it.

Executors need to fill in the IHT400 form upon someone’s death to report the full value of their estate. The IHT403 form has to be filled in alongside it to disclose lifetime gifts.

Delays in this form-filling process can mean a longer wait for probate to be granted and can increase the risk of queries from HMRC, further prolonging the closure of the estate.

4. Not having important conversations

IHT disputes among families are on the rise, so having honest conversations with loved ones has never been more important.

This can prevent legal costs racking up and delays in probate being granted, leaving you unable to deal with the estate.

Moffat says: “Having good, open conversations about gifts or what a person’s wants and wishes are for what’s to happen after their death could prevent costly legal action at what is a difficult and emotional time for family, friends and loved ones.”

5. Forgetting the £2 million taper

The residence nil-rate band starts to reduce by £1 for every £2 your estate is worth more than £2 million.

Once someone’s estate reaches £2.35 million, the £175,000 residence nil-rate band is lost completely. A surviving spouse completely loses their residence nil-rate band once their estate breaches £2.7 million.

Moffat says: “For people who might be close to this bracket it’s important to know this as they’ll need to keep an eye on how much their total estate will be worth.

“They could take steps to reduce it to below £2 million using some of the options to gift during their lifetime, meaning the residence nil rate band is available again.”

6. Not considering where inheritance tax should be paid from

If you make a larger gift which is not covered in the gifting exemptions and exceeds your inheritance tax allowance, for example to a child or grandchild to buy a house, and then die within seven years, IHT could be owed on that gift.

The beneficiary of the gift may not be able to pay this bill if it comes unexpectedly, the gift is tied up in property or has already been spent.

To reduce the risk of this, the donor of the money could take out a ‘gift inter vivo’ life insurance policy. This would cover the cost of the eventual IHT bill for the beneficiary, should you die within seven years.

Typically, these policies pay out less over time, as taper relief is applied to the IHT liability depending on when a gift was made.

For example, if you make a larger gift and die less than three years later, it would be taxed at 40%, but if you die six to seven years later, the rate drops to 8% on the gift.