Under Probate Code 24(c) and 17200, the successor in interest to a person who has a present or future interest in a trust is a “beneficiary” with standing to request an accounting from the trustee. Here, the trial court wrongly dismissed a petition to compel an accounting at a case management conference based on the trustee’s objection without giving prior notice that matters concerning the merits would be considered at the conference and without taking evidence on the contested factual issues underlying the trustee’s objection to the accounting petition.