It gave the force of law to the Anglo-Irish Treaty, which was scheduled to the Act.

Until the expiration of one month from the passing of the Act of Parliament for the ratification of this instrument, the powers of the Parliament and the Government of the Irish Free State shall not be exercisable as respects Northern Ireland, and the provisions of the Government of Ireland Act, 1920, shall, so far as they relate to Northern Ireland, remain of full force and effect, and no election shall be held for the return of members to serve in the Parliament of the Irish Free State for constituencies in Northern Ireland, unless a resolution is passed by both Houses of the Parliament of Northern Ireland in favour of the holding of such elections before the end of the said month.12.

If before the expiration of the said month, an address is presented to His Majesty by both Houses of the Parliament of Northern Ireland to that effect, the powers of the Parliament and Government of the Irish Free State shall no longer extend to Northern Ireland, and the provisions of the Government of Ireland Act, 1920 (including those relating to the Council of Ireland), shall so far as they relate to Northern Ireland, continue to be of full force and effect, and this instrument shall have effect subject to the necessary modifications.Notably, the Act (under Section 1(5) of the Act) was stated explicitly not to be the Act of Parliament for the ratification of the Anglo-Irish Treaty.

[4] That function was to fall to the Irish Free State Constitution Act 1922.

That government had constituted itself on 14 January 1922 and had since chosen Michael Collins as its chairman.