(1)This section applies if—
(a)a deductible payment is made by the former employee (and not by the former employer on behalf of the former employee), but
(b)the whole or a part of the cost of making the payment is borne—
(i)by the former employer, or
(ii)out of the proceeds of a contract of insurance.
(2)No deduction of the amount of the cost borne as mentioned in subsection (1)(b) (the “relevant amount”) may be made under section 555.
(3)But this is subject to subsection (4) if the whole or a part of the relevant amount is treated—
(a)as a relevant retirement benefit of the former employee, or
(b)as post-employment earnings of the former employee.
(4)In such a case, a deduction of so much of the relevant amount as is treated in that way may be made under section 555.