Finance Act 1950

(2) Where a disposition or determination of an interest limited to cease on the death was bona fide effected or suffered five years before the death (or, if it was effected or suffered for public or charitable purposes, one year before the death), the disposition or determination shall be excepted by this subsection—

(a) if bona fide possession and enjoyment of the property in which the interest subsisted was assumed immediately thereafter by the person becoming entitled by virtue of or upon the disposition or determination and thenceforward retained to the entire exclusion of the person who immediately before the disposition or determination had the interest and of any benefit to him by contract or otherwise; or

(b) in the case of a partial determination, if the conditions specified in the preceding paragraph were not satisfied by reason only of the retention or enjoyment by the deceased of possession of some part of the property, or of some benefit, by virtue of the provisions of the instrument under which he had the interest;

Provided that nothing in this subsection shall be construed as affecting any charge of estate duty arising otherwise than by virtue of the provisions of the preceding subsection.