Around 5.33 million Brits run the risk of leaving their loved ones in financial trouble if they can no longer work due to illness or death.
That is because these consumers have failed to update their life insurance cover following a significant change in their lives.
Sainsbury's Finance has found that 60 per cent of those with life insurance fail to notify their provider if something changes in their life, such as buying a house, meaning that their loved ones may miss out on some money.
David Cook of Sainsbury's life insurance, said: "Many people invest in life insurance when they buy their first home as they want peace of mind that they're covered should anything happen and they're unable to pay the mortgage.
"However, clearly people are overlooking the need to update their level of cover once their personal circumstances have changed."
The report found that the most common change in personal circumstance that life insurance holders experience is moving jobs (3.58 million).
This is followed by having children, which was cited by 2.75 million consumers, and getting married (1.71 million).
Mr Cook added: "Life insurance provides financial cover should the unthinkable happen and enables people to be secure in the knowledge that their dependants would receive sufficient funds if they were to die, which would help them to protect their standard of living."
Brits looking for life insurance could use the price comparison site MoneyExpert.com, as they enter their details once. After this all the available premiums are listed with their prices.
A recent report by Scottish Widows found that 28 million Brits do not have any life insurance at all, putting their loved ones at risk of financial hardship.
Around 23 per cent of those who do not have life insurance think it is too expensive, while another 20 per cent of Brits would rather cut back on their cover than live without broadband.