You may wish to consult paragraphs 9(4) and 9(5):
(4)The notice must be given by—
(a)handing it to the keeper, or leaving it at a current address for service for the keeper, within the relevant period; or
(b)sending it by post to a current address for service for the keeper so that it is delivered to that address within the relevant period.
(5)The relevant period for the purposes of sub-paragraph (4) is the period of 14 days beginning with the day after that on which the specified period of parking ended.