At some time in the life of any trust it may come to an end. Under the Rule against Perpetuities the trust will last only 80 years; with the exception being South Australia where there is no time limit for the trust. Winding up the trust at the end of its life is known as vesting. Generally any unit trust deed has a process to vest the trust at the end of 80 years or prior with the trustees or the unitholders consent and determination.