14(1)Where an earner’s earnings paid in any period before the tax year 1987-88—
(a)exceeded the lower earnings limit; but
(b)were not such that primary Class 1 contributions within Bracket 3 fell to be paid in respect of them,
it shall be assumed for the purposes of sections 54(4) and 57(2) that his earnings paid in that period were such that, taking the rate specified in Bracket 3 as the appropriate rate, the same amount of primary Class 1 contributions fell to be paid in respect of them as in fact fell to be paid in respect of them; and in this paragraph “Bracket 3” has the meaning given in section 9(3) of the M1Social Security Contributions and Benefits (Northern Ireland) Act 1992.
(2)Section 59(3) applies for the purposes of sub-paragraph (1), in so far as it applies as respects section 54(4), as if the reference in paragraph (b) of section 59(3) to earnings included a reference to earnings relevant for any purpose of that sub-paragraph.
(3)Where the Department has acted in pursuance of section 59(3) as applied by sub-paragraph (2) and it subsequently ascertains the amount of those earnings—
(a)if it appears to the Department that the amount of the contributions equivalent premium would have been less if the Department had not made the calculation on the basis described in sub-paragraph (1), it shall refund the difference to the prescribed person, and
(b)if it appears to the Department that that premium would have been greater if the Department had not done so, the prescribed person shall pay the difference to the Department.