If a decedent (person who is deceased) has real property or tangible personal property in a state other than the state where the decedent lived at the time of death (primary residence or domicile), an ancillary probate proceeding in the other state where the property is located will probably be necessary to transfer title to the property—unless, for example, the decedent took steps to transfer title to the property before death. After the domiciliary probate process is initiated in the state of the decedent’s primary residence, the executor or administrator of the estate may open an ancillary probate proceeding in the state where the property is located.

The ancillary probate is usually an abbreviated process that relies in whole or in part on the domiciliary probate court’s admission or acceptance of the will for probate. Thus, any challenges to the validity of the will generally must be made in the domiciliary probate court. And once the domiciliary probate court admits the will to probate and grants the executor or administrator authority to act on behalf of the estate (letters testamentary, letters of administration), the executor may file a copy of the will and the letters testamentary or letters of administration in the ancillary probate court. The ancillary probate court will then admit the will to probate in that state as a foreign will, giving the executor or administrator the authority to transfer or sell the property in the ancillary probate state.

In New York, when a decedent owns real property or tangible personal property in a state other than their state of domicile at the time of death, an ancillary probate proceeding is often required in the state where the property is located. This is to ensure the proper transfer of title to the property. The process begins with the primary probate proceeding in the state of the decedent's domicile, where the will is admitted to probate and the executor or administrator is granted authority to act on behalf of the estate. Subsequently, the executor or administrator can initiate an ancillary probate proceeding in the other state by submitting a copy of the will and the letters testamentary or letters of administration. The ancillary probate court will recognize the will as a foreign will and grant the executor or administrator the authority needed to manage, transfer, or sell the property in that state. Challenges to the will's validity are typically addressed in the domiciliary probate court, not the ancillary probate court.