A further 22% of those surveyed by investment provider and platform Hargreaves Lansdown were even unsure if they had a forgotten pension.

Younger savers were most likely to have lost track of a pension, with 44% of 18 to 34-year-olds saying they had, in comparison to just 7% of over-55s.

Many savers had multiple pension pots.

Close to a third (31%) of those surveyed said they had three or more pensions.

Helen Morrissey, head of retirement analysis at Hargreaves Lansdown, said many Britons are underestimating the impact of having lost a pension pot.

She said: “According to research from the Pensions Policy Institute the average size of a lost pot is more than £9,000. For some people, the pensions found are worth much more so the issue of lost pensions can have a huge effect on retirement planning. 

“Finding a lost pension could be the difference between struggling to make ends meet or being more comfortable in retirement. It’s vitally important to keep contact details for pensions up to date. If you think you have lost track of a pension, contacting the government’s pension tracing service can help.”

• Hargreaves Lansdown surveyed 2,000 British savers via Opinium in May.