Post Office staff in Hounslow are hoping to get their hands on some of the £1.9million of unused holiday cash lying around in people's homes as part of a charity fundraising bid.
They have set up a collection box at the branch in Hounslow High Street and are appealing for customers to bring in their unwanted foreign currency, after research suggested each adult is hoarding around £11.
All the money donated will go to children's charity Barnado's, which works with 100,000 children and their families affected by issues such as poverty, disability and abuse.
Hounslow branch manager Jag Shah said: "We sell a lot of currency here but don't see that many people bringing their leftover coins back.
"If customers are coming in anyway they can bring whatever coins or notes they find around the house. It'll all go to a really good cause."
The collection box arrived at the store, located upstairs in WH Smiths, last week and may become a permanent feature if enough holidaymakers drop off their leftover coins and notes.