5. In each of sections 15(3) and 18(1) of the Act(1) and sections 15(3) and 18(1) of the Northern Ireland Act(2) (Class 4 contributions recoverable under the Income Tax Acts and under regulations)—
(a)for “£4,535” (lower limit) in each place where it appears, substitute “£4,615”; and
(b)for “£29,900” (upper limit) substitute “£30,420”.