Probate Code § 10950

(a) On its own motion or on petition of an interested person, the court may order an account at any time.

(b) The court shall order an account on petition of an interested person made more than one year after the last account was filed or, if no previous account has been filed, made more than one year after issuance of letters to the personal representative.

(c) The court order shall specify the time within which the personal representative must file an account.