The Identity Cards Act 2006 was an Act of the Parliament of the United Kingdom that was repealed in 2011. It created National Identity Cards, a personal identification document and European Economic Area travel document, which were voluntarily issued to British citizens. It also created a resident registry database known as the National Identity Register (NIR), which has since been destroyed. In all around 15,000 National Identity Cards were issued until the act was repealed in 2011. The Identity Card for Foreign nationals was continued in the form of Biometric Residence Permits after 2011 under the provisions of the UK Borders Act 2007 and the Borders, Citizenship and Immigration Act 2009.

An identity document is any document that may be used to prove a person's identity. If issued in a small, standard credit card size form, it is usually called an identity card, or passport card. Some countries issue formal identity documents, as national identification cards that may be compulsory or non-compulsory, while others may require identity verification using regional identification or informal documents. When the identity document incorporates a person's photograph, it may be called photo ID.