This Travel Identity Card, was issued by The Passport Office, Liverpool. This had to be carried at all times and was a kind of internal passport, which permitted movement between the British Isles, Northern Ireland and Eire (Republic of Ireland).
Border controls were imposed on the northern side of the border in July 1940. The Northern Ireland government passed legislation requiring anyone in Northern Ireland, aged 14 and over, to hold an approved identity document.
Before this, the was an agreement that provided UK law to deem Irish Free State to be part of the UK for the purposes of immigration law. It was fully implemented in 1925 as in itself established a Common Travel Area (CTA). However, it was suspended on the outbreak of war in 1939 and travel restrictions were introduced between the islands of Great Britain and Ireland. Travel restrictions also applied to people travelling from Northern Ireland to elsewhere in the UK.
The immigration controls between the islands of Ireland and Great Britain lasted until 1952.