With Brits returning from summer holidays abroad the amount of foreign currency stashed away at home is likely to rise.
On average Brits have £49.56 ($68.21) in spare foreign cash with the most common currencies being Euros and US Dollars.
One in twenty also have Swiss Francs, Indian Rupees or Japanese Yen.
An estimated £867 million in foreign currency is sitting unused in British homes according to a recent survey by money app, Monese.
People often don't convert the money back into UK currency because they think it is not worth anything or it is too small an amount to exchange.
But there are a growing number of online platforms that will exchange any denomination of foreign currency, including coins and decommissioned currencies.
They exchange hundreds of global currencies as well as withdrawn and discontinued foreign notes and coins. For example Leftover Currency accept all 19 pre-Euro currencies as well as obsolete currencies from outside the Eurozone which banks will not take.
The website gives an online quote of what your currency is worth and this price is held for a set number of days. This gives customers time to post the currency to the company before being paid via bank transfer, PayPal or cheque.
The currency does not need to be separated so customers can send a mixture of change from a variety of countries.
Is it worth it?
There are no hidden fees such as commission for the exchange but customers do need to factor in postage costs particularly for coins which are heavier than notes.
For example a small parcel of currency from weighing up to 2kg will cost £3.20 to send second class, untracked. It is worthwhile packaging coins in bubble wrap to make the parcel more secure.
Leftover Currency will refund postage costs for packages over 1kg in most cases.
If you cannot exchange your currency anywhere else and have more than £10 worth then paying for postage may be worth it. But if you can exchange the money elsewhere in person, even at a weaker exchange rate, this may be more cost effective.
And although they have an extensive range, not all currencies are available on these websites with less common notes and coins such as Ghanaian Cedis more difficult to exchange.
Gifting coins to charity is another option and sites like Cash4Coins offer this service via post. The company is partnered with charities such as the Oxfam, Hospice UK and Alzheimer's Society and will take donations of old and unwanted currencies including coins.
You can also donate any currency of any age to The Royal British Legion at your local Sainsbury's Travel Money Bureau by simply popping it in the donation box.
And if you want to keep your foreign currency as a keepsake there are lots of creative ways to display it, with Pinterest users sharing lots of artistic suggestions.
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