The rule against perpetuities (also known as the rule against remoteness of vesting) requires that future trust interests (that is, interests that do not take effect immediately) must be certain to vest within a defined period of time known as the perpetuity period.

For example, Catherine creates a trust to pay income to her husband, Colin, for life, then to hold the capital for her son, Charles, if he survives Colin. Charles' contingent interest must be certain to vest within the perpetuity period that applies to the trust. If it is not certain to do so, it is void at common law.

Interests that are void at common law may be saved by provisions of the Perpetuities and Accumulations Act 2009, the Perpetuities and Accumulations Act 1964 or the Law of Property Act 1925. The Perpetuities and Accumulations Act 2009 also restricted the scope of the rule with effect from 6 April 2010.

For more information, see Practice notes, Perpetuities and trusts: overview and Perpetuities and Accumulations Act 2009: changes to rules.