Martin Lewis explains 'most lucrative' action anyone aged 40 to 73 should know

Making your money work for you is not a simple task and for many people, sticking funds into a savings account is about as close to making an investment as they get. But millions of people are unaware that they could do one simple thing with their money, that Martin Lewis has described as the "most lucrative thing" a person over 40, or under 73, can do.

Ensuring that you have enough money to live comfortably in retirement is never easy and if you have gaps in your National Insurance record, you could end up receiving a lower amount of State Pension when you retire. This could cost you thousands in your retirement, but, it has never been easier to fill these gaps, making an £800 payment turn into £5400 by the time you retire.

Many people do not realise that they have gaps in their National Insurance record, which is built up by continuous years of National Insurance Contributions, which are paid on all wages over the £12,570 tax threshold. If your pay has fallen below this, or you have spent some time outside of work, you could have gaps that mean you end up with less money when you retire.

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The Money Saving Expert, Martin Lewis, has previously said: "There is a potentially unbeatable opportunity everyone aged 40 to 73(ish) needs to consider.

"You've got until 5 April 2025 to buy back any missing national insurance years from 2006 to 2016. This can prove very lucrative, as some are on course to make over £50,000 in boosts to their state pension."

After April 5 2025, workers will only be able to fill in gaps from the previous six years of their employment record, so it could be worthwhile paying to fill in your record even if you are under 40. This is also true for those over the State Pension age, who can pay to fill in any remaining gaps and boost their monthly payments.

People in receipt of some benefits, National Insurance Credits can be claimed to ensure there are no gaps when sick or unemployed. To fill in any gaps in your National Insurance record, you can download the HMRC app and quickly check which years you are missing, or phone 0300 200 3500.