12.—(1) The fee for–
(a)the carrying out or supervision, by or on behalf of the Secretary of State, of an examination of a vehicle or a vehicle part; and
(b)any associated administrative work (other than the issue of a sound level measurement certificate or any document of a type specified in Schedule 3 or 4),
shall be paid when the applicant is notified by the Secretary of State of the amount payable.
(2) Any fee payable in accordance with paragraph (1), other than a fee payable by virtue of regulation 5 or 6, shall, subject to paragraphs (3) and (4), be calculated by reference to the Secretary of State’s estimate of the duration of the work likely to be required.
(3) If during the course of the work the Secretary of State estimates that the duration of the work likely to be required is greater than that estimated under paragraph (2), the fee shall be recalculated by reference to that greater estimate, and the excess, if any, over the fee originally payable shall be paid by the applicant.
(4) If the duration of the work actually required is greater or less than its estimated or re-estimated duration, the fee shall be recalculated by reference to the actual duration and the difference shall be paid by, or, as the case may be, refunded to, the applicant.
(5) The fee for the issue of a document specified in Schedule 3 or 4 shall be paid–
(a)in the case where the examination of the vehicle or vehicle part is required before the document is issued, when the applicant is notified of the result of the examination; and
(b)in any other case, when the application is made for the issue of the document.
(6) The fee for the issue of a sound level measurement certificate shall be paid when the application is made for the issue of the certificate.