A perpetuity period applies to future interests in assets (that is, interests that do not take effect immediately) that are subject to the rule against perpetuities (www.practicallaw.com/resource.do?item=:47090438). The perpetuity period may be:
A prescribed statutory period of 125 years, under the Perpetuities and Accumulations Act 2009.
An optional statutory period of up to 80 years, under the Perpetuities and Accumulations Act 1964.
The common law period, which is the lifetime of the last to die of certain individuals alive when the interest is created (known as "lives in being" or "measuring lives") plus 21 years.