These shall be recoverable, in the proceedings in execution of every certificate,-

(a) an interest at the rate of two per centum for each British calender month from the date of immediately following the end of the period of time specified in the notice referred to in rule 2 upon the amount of tax, penalty, late fee or interest or other sum to which the certificate relates, and

(b) all charges incurred in respect of -

(i) the service of notice upon the defaulter to pay the arrears of tax, penalty, late fee or interest, and of warrants and other processes, and

(ii) all other proceedings taken for realising the arrears of tax, penalty, late fee or interest.