(1)In this Chapter “capital sum” means—
(a)any sum paid by way of loan or repayment of a loan, and
(b)any other sum which—
(i)is paid otherwise than as income, and
(ii)is not paid for full consideration in money or money’s worth.
(2)But this is subject to subsections (3) to (6).
(3)It does not include any sum which could not have become payable to the settlor except—
(a)in one of the circumstances mentioned in subsection (2) of section 625, or
(b)on the death under the age of 25 of any person of the kind mentioned in subsection (3) of that section.
(4)It does include a sum treated as a capital sum by subsection (5) below.
(5)Any sum which—
(a)is paid by the trustees of a settlement to a third party—
(i)at the settlor’s direction, or
(ii)as a result of the assignment by the settlor of the settlor’s right to receive the sum, or
(b)is otherwise paid, or applied by, the trustees for the benefit of the settlor,
is treated as a capital sum paid to the settlor by the trustees.
(6)Subsection (5) does not apply to any sum which would, apart from that subsection, be treated as a capital sum paid to the settlor.
(7)References in sections 633 to 638 to sums paid to the settlor include references to sums paid to—
(a)the spouse of the settlor, or
(b)the settlor (or the spouse of the settlor) jointly with another person.