One employment is associated with another if—

1. (a)

   the employer is the same;

2. (b)

   the employers are partnerships or bodies and an individual or another partnership or body has control over both of them; or

3. (c)

   the employers are associated companies (as defined in section 416).

   Section 168(12) (meaning of “control”) applies for the purposes of paragraph (b).

1. (3)

   The Treasury may by regulations amend sub-paragraph (2) so as to alter the rates or rate bands.