[1] It was the British implementing measure for the 1938 Anglo-Irish Agreements which were signed at London on 25 April 1938 by the governments of Ireland and the United Kingdom.

There were three agreements in total: one to rescind Articles 6 and 7 of the Anglo-Irish Treaty and the transfer of British Admiralty property to Ireland; a second for the settlement of outstanding financial claims against the Irish Government; and the third, an important trade agreement putting an end to an "economic war" between the two countries.

[2] Under Section 1 of the Act, it was declared that (for the purposes of United Kingdom legislation) the territory "which was ... known as Irish Free State shall be styled as...Eire".

[5] One of the Act's effects was to throw into doubt whether Irish citizens were still British subjects.

Legal arguments were raised that as the Constitution of Ireland declared Ireland a sovereign independent state, the passing of the Act which recognised one of the Irish state’s constitutional names, also recognised its sovereignty.