CG37711 - Absolute entitlement: special cases: class closing rules: introduction
If the class is not closed, then the trustees cannot distribute the property to the beneficiaries because they cannot tell whether the apparent share of a particular beneficiary will be reduced by the addition of further members to the class. Therefore absolute entitlement is deferred. The trustees may however be able to exercise the power of advancement, see CG37330(b), to pass property to beneficiaries.