With a brand new tax year due to start in just under three weeks time and plenty of changes on the horizon for benefits, bills and personal finances, Money Saving Expert Martin Lewis was once again on hand on Tuesday evening to lift the lid on the nation’s most pressing financial questions and concerns, while also hopefully saving the public some hard earned cash.

One of the key points made in the financial guru’s programme: The Martin Lewis Money Show Live, was to check your tax code is correct, or risk losing out on potentially thousands of pounds.

The small code, which can typically be found on payslips, lets your pension provider or employer know how much tax to charge you, but as Martin pointed out, many of these codes across the country are actually incorrect.

He told audiences: “Urgently check if yours is correct, but more importantly – for the backdating, was correct in 2020/2021. Your tax code tells your employer or pension provider what tax to take from you.

“It normally looks something like this (1275L) – this is the typical one. Just so you know, add a 0 at the end and a £ at the beginning and that’s your personal allowance, or how much you can earn tax free each year. That’s what the tax code is saying.”

Using Martin’s example, the UK’s most common tax code 1275L, means a person has a tax-free allowance of £12,750 each year.

“Now, millions of these are wrong,” continued Lewis. “And the crucial thing here, is that it is not HMRC’s responsibility, it is not your employer’s responsibility, it is YOUR responsibility to make sure it’s right.”

He also went on to highlight that this is the public’s last opportunity to reclaim any tax from overpayments in the 2020/2021 tax year as he urged viewers to urgently check their tax code or risk losing out on their hard earned cash.

“You may have overpaid hundreds or thousands of pounds in 2020/2021 – this is your last opportunity to check if that’s right,” he explained, before revealing just how to go about checking. “So go online to a tax code calculator which will explain what it meant and check if it is right, because if not you’re going to miss the opportunity to get it back if you overpaid.”

While overpayments may have a strict deadline to claim any money back, it turns out the same isn’t quite so true for the government – as any underpayment of tax can still be pursued for a far longer period of time, meaning you’ll still have to pay up if the calculation was wrong.