Where there’s a will there’s a claim, as any witty probate solicitor will tell you. And, as inheritance legislation turns 50, it seems that it is not just a joke but a reality for a rising number of people.

Claims brought in the High Court in London under the Inheritance (Provision for Family and Dependants) Act 1975 have risen from eight in 2004 to 205 last year, according to figures published by the Royal Courts of Justice.

In addition, in the last three months of 2024 the number of applications to block probate — the process of validating a will — hit a record high of 3,061 in a quarter, figures obtained by Taylor Rose Solicitors reveal.

In total in 2024, the data — obtained under the Freedom of Information Act from the courts and tribunals service — showed there were 11,362 applications during the year, compared with 7,268 in 2019 and 6,358 in 2010, the earliest year for which the statistics are available.

Meanwhile, a survey of 2,000 adults for Level, a lender that provides finance for family law and probate disputes, found that 38 per cent said they would go to court to dispute a will if they thought their inheritance was unfair.

The Inheritance Act allows certain relatives or dependants to make a claim against an estate of a deceased where they have not been given “reasonable financial provision” in the will, or as a result of an intestacy. If eligible claimants — who may include a spouse, former spouse, children, civil partner, some cohabitants and other dependants — have been left out of a will, a judge can award them a share of the estate if they can show that they have been unfairly left without support.

When the act was introduced, it marked a radical change by providing married women with a fairer share of their husband’s estate than 1930s legislation had, giving them a proper share of all marital assets, rather than maintenance payments. The law also removed several restrictions that had barred unmarried daughters and sons over the age of 21 from making a claim for assets in their parents’ estate.

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The inheritance rules became “a lot more equitable” and had a huge practical impact on the living standards of surviving wives, who had previously ended up with less than if they had divorced their partners, says Stuart Downey, a partner at the law firm TWM.

When the act was implemented it was intended “as a bit of a backstop to prevent obvious cases of injustice where a family member — or obvious dependant — had been excluded unfairly”, explains Daniel Edwards, a partner at Browne Jacobson. He attributes the rise in claims made under the act — which he anticipates will continue — to a combination of an ageing population, more “blended” families and greater public awareness of individual rights.

Melinda Giles, the managing partner at Giles Wilson, suggests that the act is used in an entirely different way now than when it was introduced. “Now we have blended families, we have grandchildren living rent-free with grandparents because they cannot afford to live anywhere else,” Giles says, warning that “providing a roof over a head” is seen by the courts as a dependency claim.

“People are walking into those claims without any idea sometimes that a contentious probate is potentially the legacy that they will leave behind,” she says. “If you are prepared to provide for someone financially during your lifetime, why would you not provide for them on your death?”

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The legislation “does jar with the concept of testamentary freedom”, suggests Andrew Bishop, a partner at Rothley Law, but he says it “tries to strike an important balance between complete freedom and ensuring certain family and dependants are not left destitute and possibly reliant on state benefits for support”.

Fifty years after receiving Royal Assent, experts warn that the law has not kept in step with changing social norms and relationships, and needs reform, particularly for the growing number of cohabiting couples. While a married couple are entitled to lifestyle provision under the act, no matter how short the marriage was, an unmarried couple who may have lived together for decades are only entitled to a low standard of “maintenance”, Bishop says.

Blended families with children from previous marriages may also face difficulties when making claims to their parents’ estate, Downey says.

In May the Law Commission, the body that advises ministers on reform in England and Wales, recommended that those two groups be given greater powers to bring claims. It also suggested modernising the mostly Victorian-era law on wills to enable electronic documents and to abolish the rule that a marriage or civil partnership revokes a bequest.

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Six months on the government is still considering those recommendations and Mark Evans, the president of the Law Society, which represents solicitors in England and Wales, urges ministers to “act quickly” to revise the Inheritance Act and the Wills Act 1837 or “risk leaving many people’s final wishes unprotected”.

Meanwhile, 19 weeks after the government withdrew the “Bona Vacantia” list of unclaimed estates after an increase in fraud, Neil Fraser, a partner at the probate research firm Fraser and Fraser, warns that hundreds of estates remain off the public record, potentially denying thousands of rightful heirs their inheritance.