What is a mandatory trust?

A mandatory trust is the most restrictive form of trust, where the trustee has no discretion and the trust document specifically lays out and details how the beneficiaries are supposed to receive the property. For example, a mandatory trust for a bank account may say that the trustee is required to pay the beneficiary $1,000 a month, on the first of each month, for the next 10 years, with no deviations to this payment schedule.

This is opposed to a discretionary trust, which does leave some amount of discretion to the trustee.