The USA for example has a law which requires an alien to carry [immigration documents / ID](https://www.uscis.gov/ilink/docView/SLB/HTML/SLB/0-0-0-1/0-0-0-29/0-0-0-8289.html) on their person at all times. When flouted it is a misdemeanor and punishable by up to 30 days imprisonment.

> Every alien, eighteen years of age and over, shall at all times carry
> with him and have in his personal possession any certificate of alien
> registration or alien registration receipt card issued to him pursuant
> to subsection (d). Any alien who fails to comply with the provisions
> of this subsection shall be guilty of a misdemeanor and shall upon
> conviction for each offense be fined not to exceed $100 or be
> imprisoned not more than thirty days, or both.

Does such a law for aliens exist for the UK and does my credit/debit card with my name suffice as ID (not for driving, just for example if a ticket officer wants to check my ID on the metro) in the UK?