Library card
From Tardis Wiki, the free Doctor Who reference
A library card was a form of identification used to borrow books from libraries. The First Doctor received a library card from Shoreditch Library having registered there sometime between his arrival in May 1963 and November 1963, when the card was due to expire. The Doctor kept the library card as he departed Shoreditch on 22 November and retained it to as late as his eleventh incarnation, who mistakenly presented it as his identification to a group of Saturnyns. Having never renewed it, the card still sported the image of his first incarnation. (TV: The Vampires of Venice)