Students with their immigration permission on BRP (Biometric Residence Permit) cards are reminded to keep them somewhere safe. It is not a requirement to carry the card with you in the UK.
Many students have lost their BRP cards recently and applying to replace them takes a long time (about eight weeks for the standard service) and is expensive. If you lose your BRP card, you will not be able to travel and return to the UK until you receive your replacement. See the process for replacing a BRP card here.
You can buy a proof of age card as evidence of your age to buy alcohol and enter pubs and clubs so that you don’t need to carry your BRP card. See: www.pass-scheme.org.uk.