Hi Guys, here is my Dad's identity card which was issued to him, as a child, in May 1940.
The National Registration Card was issued to everyone in Great Britain. Introduced in 1939 at the outbreak of war. It had to be carried at all times if you were an adult and shown upon demand to the Police etc. Initially, all cards were coloured brown like my Dad's example, but in 1943 a new blue coloured card was introduced for adults.
Cheers, Ade.