Section 3–201. [Venue for First and Subsequent Estate Proceedings; Location of Property.]
(a) Venue for the first informal or formal testacy or appointment proceedings after a decedent's death is:
(1) in the county where the decedent was domiciled at the time of death; or
(2) if the decedent was not domiciled in the commonwealth, in any county where property of the decedent was located at the time of death.
(b) Venue for all subsequent proceedings within the exclusive jurisdiction of the court is in the place where the initial proceeding occurred, unless the initial proceeding has been transferred as provided in section 1–303 or (c) of this section.
(c) If the first proceeding was informal, on application of an interested person and after notice to the proponent in the first proceeding, the court, upon finding that venue is elsewhere, may transfer the proceeding and the file to the other court.
(d) For the purpose of aiding determinations concerning location of assets which may be relevant in cases involving non-domiciliaries, a debt, other than one evidenced by investment or commercial paper or other instrument in favor of a non-domiciliary is located where the debtor resides or, if the debtor is a person other than an individual, at the place where it has its principal office. Commercial paper, investment paper and other instruments are located where the instrument is. An interest in property held in trust is located where the trustee may be sued.