4.—(1) Subject to paragraphs (2) and (3) the period during which a certificate is in force shall commence on the day specified in the certificate as being the date on which it comes into force and shall continue for the life of the person concerned.
(2) The period specified in paragraph (1) shall not commence—
(a)in the case of a vehicle scheme beneficiary who on or after 1st August 1977 is receiving payments in pursuance of section 33(3) of the Health Services and Public Health Act 1968 in respect of a vehicle belonging to him, before 5th July 1978; or
(b)in relation to any other vehicle scheme beneficiary—
(i)before 16th November 1977 if his surname begins with any of the letters from A to K in the alphabet; or
(ii)before 15th February 1978 if his surname begins with any of the letters from L to Z in the alphabet.
(3) If in any case the Secretary of State determines that the condition specified in regulation 3(2)(b) is not satisfied, the certificate shall cease to be in force from the date of such non-satisfaction as determined by the Secretary of State (or such later date as appears to the Secretary of State to be reasonable in the circumstances).