Exception from Class 4 liability of persons over pensionable age and persons not resident in the United KingdomU.K.
91. Any earner who—
(a)at the beginning of a year of assessment is over pensionable age; or
(b)for the purposes of income tax is not resident in the United Kingdom in the year of assessment;
shall be excepted from liability for contributions under section 15 of the Act (Class 4 contributions).