More than one in four Britons (38%) expect an inheritance, or have already received one, according to the study from Hargreaves Lansdown.

The study found that the percentage of those relying on an inheritance peaked in the years before retirement (55-64), with 45% of that age group relying on one.

Half of parents with children living at home (47%) said they needed an inheritance to help provide a decent income in retirement.

Women were also more likely to need a windfall for their retirement income.

Helen Morrissey, senior pension finance analyst at Hargreaves Lansdown, said: “An inheritance can play a role in retirement planning, but you need to consider it carefully. Your essential expenses should be covered regardless of whether or not you get an inheritance – this can come from a combination of state pension, workplace and personal pensions as well as any other investments.

“Any inheritance should help pay for the extras to make life more comfortable – or give you the lifestyle you want in retirement. If your pension savings will fall short without an inheritance, you need a robust plan B you’re prepared to use.

“If an inheritance is likely to play some part in your retirement income, you need to be as sure as you can be that you’ll actually get one. It may feel like a tricky conversation to have with your loved ones, but you can’t base planning on a vague assumption and crossed fingers. Lifetime gifts could also be more tax-efficient.”

• Opinium surveyed 2,000 Britons in April on behalf of Hargreaves Lansdown.