Martin Lewis has issued an ‘urgent’ warning to those who still haven’t checked if they could top up their pension pot by as much as £50,000.

Most people under 73 have until 5 April to boost their state pension amounts for retirement in just a few straightforward steps. This is the deadline to ‘buy back’ any missing national insurance years from 2006 to 2018 – a crucial element in securing the most out of the state pension.

“Getting those back … that is what can be worth tens of thousands of pounds,” Mr Lewis told viewers in March. At the start of April, he delivered another ‘urgent’ warning to any followers on Twitter / X who still hadn’t checked if they could be missing out.

The government put the deadline in place to ensure that those who could be affected by the new state pension transitional arrangements have time to secure the full amount. It covers the years between 6 April 2006 and 5 April 2018, while people can continue to always fill in gaps over the last six years.

It will expire on 5 April 2025, having been extended twice before. HMRC says more than 10,000 payments worth £12.5 million have been made through their new digital service, which launched in April 2024.

However, the government has recently ‘softened’ this deadline, allowing certain pensioners to buy back missing national insurance years later than 5 April. This will apply to those who request a call back from the DWP before the deadline, which should come within 8 weeks of the request.

To qualify for the full new state pension amount, most people will need 35 full national insurance years. ‘Buying’ one of these costs £824, but will secure much more than this in the long run.

Each year filled will lead to an extra £328 a year in state pension pre-tax – meaning the investment will pay for itself in less than three years. For someone who lives for 20 years beyond retirement age, currently 66, the investment will be worth more than eight times the original amount.

In some cases, people may only need to top up a year slightly to fill it, with some cases being just £10 short. Paying this small amount of money can boost yearly retirement age income for some by hundreds of pounds.

Importantly, the maximum state pension amount is currently £221.20 a week, so those set to receive this amount won’t need to take action.

Mr Lewis’ Money Saving Expert service uses the example of a woman who found she had eight years’ worth of NI contributions missing, paying them as promptly as she could. This would have cost her up to £6,500, and boosted her state pension by £2,624 a year.

Assuming she lives for a typical 20 years after retirement, this investment would be worth £52,480 overall – more than paying for itself.

To pay for national insurance years or seek further guidance, savers can visit the HMRC website.