In regulation 103(2) (Class 4 liability of earners treated as self-employed who would otherwise be employed earners) for the words from “of an amount equal” to the end substitute—

“of an amount equal to the aggregate of—

(a)

the main Class 4 percentage of so much of the total of those earnings as exceeds the lower, but does not exceed the higher, of the money sums, and

(b)

the additional Class 4 percentage of so much of the total of those earnings as exceeds the higher of the money sums,

for the time being specified in section 18(1A)14.”.