Road Traffic Act 1991

6 (1) Where a notice to owner is served on any person and the penalty charge to which it relates is not paid before the end of the relevant period, the authority serving the notice may serve on that person a statement (a “charge certificate”) to the effect that the penalty charge in question is increased by 50 per cent. E+W+S

(2) The relevant period, in relation to a notice to owner, is the period of 28 days beginning—

(a) where no representations are made under paragraph 2 above, with the date on which the notice to owner is served;

(b) where—

(i) such representations are made;

(ii) a notice of rejection is served by the authority concerned; and

(iii) no appeal against the notice of rejection is made,

with the date on which the notice of rejection is served; or

(c) where there has been an unsuccessful appeal against a notice of rejection, with the date on which notice of the adjudicator’s decision is served on the appellant.

(3) Where an appeal against a notice of rejection is made but is withdrawn before the adjudicator gives notice of his decision, the relevant period in relation to a notice to owner is the period of 14 days beginning with the date on which the appeal is withdrawn.