This is what it says on the Citizens advice website :
Do you have a responsibility to look after the goods?
Your responsibility to look after goods left with you depends on whether you have a contract with the trader who left them.
If you have a contract with the trader for goods left behind, you are responsible for looking after the goods with a reasonable degree of care. This means you should take care to ensure the goods are not lost, damaged or stolen. If anything happens to the goods you may be deemed to have been negligent.
You could be liable to pay the trader compensation if you were negligent and something happened to the goods that you could have foreseen.
If you don’t have a contract with the trader for the goods left behind, you should look after them as if they were your own. This is a lower standard of responsibility than if you had a contract.
For example, if a builder leaves scaffolding poles in your garden that they should have taken away, you are not responsible for making sure the poles do not go rusty.
https://www.citizensadvice.org.uk/co...oods-with-you/