760 ILCS 3/817
Upon the occurrence of an event terminating a trust in whole or in part, or upon the exercise by a beneficiary of a right to withdraw trust principal, the trustee shall proceed expeditiously to make the distribution to the beneficiary. The trustee has the right to require from the beneficiary a written approval of the trust accounting provided to the beneficiary and, at the trustee's election, a refunding agreement from the beneficiary for liabilities that would otherwise be payable from trust property to the extent of the beneficiary's share of the distribution. A trust accounting approved under this Section is binding on the beneficiary providing the approval and on the beneficiary's successors, heirs, representatives, and assigns. A trustee may elect to withhold a reasonable amount of a distribution or require a reasonable reserve for the payment of debts, expenses, and taxes payable from the trust pending the receipt of a written approval of the trust accounting provided to the beneficiary and refunding agreement from a beneficiary or a judicial settlement of accounts.
760 ILCS 3/817