Before the NAfW can make an Assembly Measure on any particular topic it first has to obtain a Legislative Competence for it (See section on Legislative powers of the NafW). The Assembly can only obtain a Legislative Competence on any Matter with the approval of the UK Parliament.

There are two main procedures within Parliament through which the Legislative Competences may be obtained:

• Through an Act of Parliament

• Through a particular type of Order in Council known as a Legislative Competence Order. Legislative Competence Orders must be laid before Parliament by the Secretary of State for Wales, and approved by both Houses of Parliament and the Assembly.

Although these are the two main routes through which Legislative Competences may be obtained, some matters were added to Schedule 5 of the Government of Wales Act 2006, prior to May 2007 using a special conversion order procedure. This includes a number of matters relating to education and health.

Once a Legislative Competence has been obtained on a particular Matter then that Matter will be added to Schedule 5 of the Government of Wales Act 2006.