For the purposes of this Part, a person is a person in default if—
(a) an infringement warrant has been issued against the person; and
(b) a seven-day notice has been served on the person; and
(c) a period of 7 days after service for the seven-day notice has expired without the person—
(i) paying the amount outstanding under the infringement warrant; or
(ii) in the case of a natural person other than a director to whom a declaration under section 91 applies, applying for a payment order for the payment of the amount outstanding under the warrant; or
(iii) applying for revocation of the enforcement order.