There are less than six weeks left for millions of workers to be able to boost their state pension by thousands of pounds.

People aged roughly 45 to 70 have been issued with an urgent warning because the maximum state pension boost only remains available until April 5.

A new state pension was introduced seven years ago, on April 6, 2016, and to get it you need to have around 35 years of paying national insurance to qualify.

But as a result of career breaks, or caring for others, short periods spent unemployed or time spent abroad, potentially hundreds of thousands of people are estimated to be missing out on some of those vital years which they require to qualify for their full state pension in later life.

Those who discover they have a shortfall could be permitted to buy more years back if they need them - but time is running out to make a claim for the largest possible amount says the government.

April deadline

Until early April gaps can be plugged all the way back to 2006.

But after April 5 this year workers wishing to buy extra years will only be permitted to track back six tax years to 2017 - meaning that there will soon be 11 years which workers won't be able to enter a claim for.

MoneySavingExpert founder Martin Lewis says for anyone roughly aged 45 to 70 now is the time to check whether they've accrued enough.

In a special ITV programme this week he explained: "As discussed before, the new state pension was introduced on April 6, 2016. So this is for anybody aged under 70ish. To get it, you need 35ish qualifying national insurance years and I say 'ish', because it is just complicated. So let's go with 35ish; maybe more, maybe less in some circumstances.

"But many people are missing national insurance years – maybe because you were caring for somebody or caring for a child, or you had years abroad, or you had a low income, or you had a career break.

"Now, this is why it's so urgent. Transitional arrangements were put in place in April 2016, and they end this tax year – that is 5 April. It's about six weeks away. And that's not a long time to do something that's quite complicated."

According to latest figures from the Department for Work and Pensions, approximately 3.8million people miss out on the full state pension.

While buying back years can cost anything between £15 and several thousand depending on how much is missing - the move can add many more thousands of pounds to a person's eventual state pension.

How to check if you're missing national insurance years?

People under state pension age can check if they've got missing years using the Gov.uk pension summary, which can tell whether your pension is forecast to be at the full state level, followed by a check of your personal national insurance record to find out whether you've got missing years and where they are.

While in some cases earning back the years might be free - if for example you were caring for someone - on many occasions it requires people to make a financial contribution and claimants must then decide whether it's worthwhile or if, depending on their age, they think they've time to acquire and earn back what is missing naturally.

Buying back

National insurance contributions can be bought back for £15.85 a week - which means it costs £824.20 to buy one entire year's worth of contributions. But this can add £275 to a state pension every year.

The government's Future Pension Centre can also offer help and offer advice when it comes to pension predictions for those struggling to decide whether the boost is needed and to what extent - and the advice is to contact them before purchasing any missing credits you think you might need.

Martin Lewis said: "If you have a shortfall, you can buy more years. So if you can't get them free, you can buy them. Now, if your gaps are from 2006 to 2017, clearly you need to decide soon because the window is closing. If you're near state pension age, this is easy. You'll know whether or not you'll be able to make them up another way.

"If you're younger, you've got more time to plug the gaps naturally by working, or any other method, which makes it more difficult to see if it's worthwhile."

If you're under 45

While the pension boost and offer to buy back as far back as 2006, is likely to be most beneficial for those over the age of 45 to consider, the Money Saving Expert is encouraging all workers to spend time checking their national insurance contributions in the coming weeks.
Martin Lewis added: "It's important to understand national insurance years are binary. You either qualify for them or you don't. You don't get half a year. You either get nothing or you get the whole year.

"And it can be the case, if you're only a week short of a full year, you may be told, and you heard that's why they had the partial year that was cheaper, one week's worth, £15, may qualify you for a full year.

"So I think it's worth saying, and it's difficult this, if you were under 45 and you saw that you were really nearly getting the full year, even though it might be wasting money to buy it because you might earn the full number of national insurance years naturally anyway, you might want to consider doing it speculatively if it's really cheap for 2006 to 2017. Because this is your last chance."