Martin Lewis has warned Brits to check their piggy banks, money jars and loose change hiding spots for ‘unspendable’ notes and coins.

The Money Saving Expert founder shared his warning in his weekly newsletter full of tips and tricks to make the most of your finances.

Mr Lewis also has a number of ITV shows including The Martin Lewis Money Show and Extreme Savers.

Regular stints on Good Morning Britain and This Morning have seen him become the nation’s most trusted financial expert.

Writing in his latest MSE newsletter, the cash-saving guru warned subscriber that loose change stashed away for a rainy day may be unspendable.

The warning comes after new statistic revealed there are 114 million old Bank of England £5 paper notes and 76 million Bank of England £10 paper notes still out there.

Whilst the Royal Mint say there are around 109 million old round pound coins that have yet to be returned.

That makes for a whopping £1.4 billion that currently can’t be used, but thankfully there are several ways to make your cash spendable again.

The team at Money Saving Expert recommend heading to your bank to see if they can switch old paper notes and coins for new ones. Whilst other banks will let you deposit old money into your digital account.

Although they do states that banks “don’t legally have to accept old paper notes and coins once they've been withdrawn from circulation”.

Alternatively, you could head to the Post Office, who will deposit old paper notes and coins into your bank account, which you can then withdraw.

To do this your bank will need to be signed up to receive cash deposits via the Post Office.

The third method will only work for £5 and £10 notes, not coins.

If your local bank branch and post office cannot help, you can can swap paper notes for polymer versions at the Bank of England at Threadneedle Street, London, or apply to do this this by post.

What about £20 and £50 notes?

Whilst new Bank of England polymer versions of the £20 and £50 notes are now in circulation, paper versions are still legal tender until September 30, 2022.

You can swap your old paper notes of these in at the bank, but there is no rush to do so.