(1)This section imposes a limit on how much of an employee’s general earnings are chargeable overseas earnings for a tax year under section 23 if—
(a)in that year the employee holds associated employments as well as the employment to which subsection (2) of that section applies (“the relevant employment”), and
(b)the duties of the associated employments are not performed wholly outside the United Kingdom.
(2)The limit is the proportion of the aggregate earnings for that year from all the employments concerned that is reasonable having regard to—
(a)the nature of and time devoted to each of the following—
(i)the duties performed outside the United Kingdom, and
(ii)those performed in the United Kingdom, and
(b)all other relevant circumstances.
(3)For the purposes of subsection (2) “the aggregate earnings for a year from all the employments concerned” means the amount produced by aggregating the full amount of earnings from each of those employments for the year mentioned in subsection (1) so far as remaining after subtracting any amounts of the kind mentioned in step 2 in section 23(3).
(4)In this section—
(a)“the employments concerned” means the relevant employment and the associated employments;
(b)“associated employments” means employments with the same employer or with associated employers.
(5)The following rules apply to determine whether employers are associated—
Rule A
An individual is associated with a partnership or company if that individual has control of the partnership or company.
Rule B
A partnership is associated with another partnership or with a company if one has control of the other or both are under the control of the same person or persons.
Rule C
A company is associated with another company if one has control of the other or both are under the control of the same person or persons.
(6)In subsection (5)—
(a)in rules A and B “control” has the meaning given by section 840 of ICTA (in accordance with section 719 of this Act), and
(b)in rule C “control” means control within the meaning of section 416 of ICTA (meaning of expressions relating to close companies).
(7)If an amount of chargeable overseas earnings is reduced under step 3 in section 23(3) as a result of applying any limit imposed by this section, the amount of general earnings corresponding to the reduction remains an amount of general earnings within section 21(1).