Over a third (35%) of Britons have never reviewed their retirement plans and 29% fear they will be short of money when they retire, according to new research.

People were more likely to review their insurance costs, energy suppliers and savings rates on a regular basis than they were their pensions, according to the research for investment platform EQi.

EQi found that 35% of pension holders did not know how much they have accrued for retirement.

Almost half (42%) of those holding individual pensions did not how much they are paying in fees.

Only 4% pension holders said they review their pensions at least once a year. This is compared with the 73% who review their car insurance annually or the 17% people who said they review their savings at least once a year.

Self-employed workers took more interest in their retirement plans with 24% knowing how much they had saved across all of their pension pots, in comparison to just 14% of employees.

Many of those surveyed (14%) were unaware of SIPPs with an additional 12% saying they do not understand the rules around moving pension pots into a SIPP.

Over one in 10 (11%) said SIPPs were too complicated and they were worried they may make a mistake trying to open one.

Richard Pearson, director at EQi, said: “Our research has uncovered a massive knowledge gap amongst millions of people who seem completely disconnected from their retirement savings.

"While the introduction of auto enrolment got more people saving into a pension than ever before, it has also compounded issues surrounding awareness. A huge proportion of workers now don’t know how much they’ve saved and whether it will be sufficient to support them later on in life.

“With so many people switching jobs throughout their career, which could be 50 years long, the risk is that they end up with a trail of legacy pension pots scattered across different providers, with no single view of how they are performing and how much they are paying in fees.

"It’s ironic that in a country where consumers are urged to review their insurance policies, home energy bills and savings accounts on an annual basis to save tens of pounds, they could be losing hundreds, or even thousands of pounds on fees and poorly performing pensions, arguably the most important financial product they will ever own.”

• The nationally representative survey of 2,062 adults was carried out by YouGov for EQi in July.