Regulation (EC) No 883/2004 of the European Parliament and of the Council on the co-ordination of social security systems;

Regulation (EC) No 987/2009 of the European Parliament and of the Council laying down the procedure for implementing Regulation (EC) No 883/2004;

Regulation (EEC) No 1408/71 on the application of social security schemes to employed persons, to self-employed persons and to members of their families moving within the Community;

Regulation (EEC) No 574/72 fixing the procedure for implementing Regulation (EEC) No 1408/71;

Regulation (EC) No 859/2003 extending Regulation (EEC) No 1408/71 to nationals of non-EU Member Countries.

to make different provision for different categories of person to whom they apply (and the categories may be defined by reference to a person's date of arrival in the United Kingdom, their immigration status, their nationality or otherwise);

otherwise to make different provision for different purposes;

to make supplementary, incidental, consequential, transitional, transitory or saving provision;

to provide for a person to exercise a discretion in dealing with any matter.

any provision made by primary legislation passed before, or in the same Session as, this Act;

any provision made under primary legislation before, or in the same Session as, this Act is passed;

retained direct EU legislation which is not mentioned in subsection (2).

the Secretary of State or the Treasury,

a Northern Ireland department, or

a Minister of the Crown acting jointly with a Northern Ireland department.