In the UK, it is not a legal requirement for Identity (I.D) cards to be carried on your person. Therefore, you are advised to leave yours at your accommodation locked in your suitcase.
The occasions when you may need to show your I.D. card are:
- when purchasing tobacco or alcohol from a shop or supermarket to prove you are over the age of 18
- when purchasing tobacco or alcohol in a pub to prove you are over the age of 18
- when gaining admission to a disco or nightclub to prove your age as above
- when gaining admission to an 18-rated film at a cinema
- when using the services of a bank or post office
- when making a purchase (sometimes) in certain shops
Please note if you take a photo of your card and leave it on your phone most places will accept this as a proof of age.