Daytime TV viewers will be familiar with Sir Michael Parkinson offering a "free pen just for inquiring" about the over-50s plan of market leader Sun Life, part of Axa Wealth.

But with this plan, consumers must continue paying premiums until they die otherwise they will not get a penny back, however much they may have paid in.

A 70-year-old paying £20 per month into a Sun Life Guaranteed Over 50 Plan is promised a payout on death of £2670. If he or she lives to 100, they will have paid £7200 in premiums. Other companies requiring premiums to be paid until death include NatWest/RBS and Asda Money, which however has a guarantee that you will pay no more in premiums than the sum assured.

Sun Life said: "We make it very clear that while many receive a sum assured greater than the level of premiums paid in, others may get less."