26 C.F.R. § 301.6323(f)-1
For purposes of subparagraph (2) of this paragraph (b), the residence of a corporation or partnership is deemed to be the place at which the principal executive office of the business is located, and the residence of a taxpayer whose residence is not within the United States is deemed to be in the District of Columbia.
Example 1. The law of State X provides that notices of Federal tax lien affecting personal property are to be filed in the Office of the Recorder of Deeds of the county where the taxpayer resides. The laws of State X also provide that notices of lien affecting real property are to be filed with the recorder of deeds of the county where the real property is located. On June 1, 1970, in accordance with § 301.6323(f)-1 , a notice of lien is filed in county M with respect to the delinquent tax liability of A. At the time the notice is filed, A is a resident of county M and owns real property in that county. One year later A moves to county N and one year after that A moves to county O. Because the situs of personal property is deemed to be at the residence of the taxpayer at the time the notice of lien is filed, the notice continues to be effectively filed with respect to A's personal property even though A no longer resides in county M. Furthermore, because the situs of real property is deemed to be at its physical location, the notice of lien also continues to be effectively filed with respect to A's real property.
Example 2. B is a resident of Canada but owns personal property in the United States. On January 4, 1971, in accordance with § 301.6323(f)-1 , a notice of lien is filed with the Office of the Recorder of Deeds of the District of Columbia. On January 2, 1973, B changes his residence to State Y in the United States. Because the residence of a taxpayer who is not a resident of the United States is deemed to be in the District of Columbia and the situs of personal property is deemed to be at the residence of the taxpayer at the time of filing, the lien continues to be effectively filed with respect to the personal property of B located in the United States even though B has returned to the United States and taken up residence in State Y and even though B has at no time been in the District of Columbia.
Example 3. The law of State Z in effect before July 1, 1967, provides that notices of lien affecting real property are to be filed in the office of the recorder of deeds of the county in which the real property is located, but that if the real property is registered under the Torrens system of title registration the notice is to be filed with the registrar of titles rather than the recorder of deeds. The law of State Z in effect after June 30, 1967, provides that all notices of lien affecting real property are to be filed with the recorder of deeds of the county in which the real property is located. Accordingly, where the Torrens system is adopted by a county in State Z, there were before July 1, 1967, two offices designated for filing notices of Federal tax lien affecting real property in the county because one office was designated for Torrens real property and another office was designated for non-Torrens real property. Because State Z had not designated one office within the State, county, or other governmental subdivision for filing notices before July 1, 1967, with respect to all real property located in the State, county, or governmental subdivision, before July 1, 1967, the place for filing notices of lien under this section, affecting property located in counties adopting the Torrens system, was with the clerk of the U.S. district court for the judicial district in which the real property is located. However, after June 30, 1967, the place for filing notices of lien under this section, affecting both Torrens and non-Torrens real property in counties adopting the Torrens system is with the recorder of deeds for each such county. Notices of lien filed under this section with the clerk of the U.S. district court before July 1, 1967, remain validly filed whether or not refiled with the recorder of deeds after the change in State law or upon refiling during the required refiling period.
Example 4. The law of State W provides that notices of lien affecting personal property of corporations and partnerships are to be filed in the office of the Secretary of State. Notices of lien affecting personal property of any other person are to be filed in the office of the clerk of court for the county where the person resides. Because the State law designates only one filing office within State W with respect to personal property of any particular taxpayer, notices of lien filed under this section, affecting personal property, shall be filed in the office designated under State law.
Example 5. The law of State F provides that notices of lien affecting personal property are to be filed with the clerk of the circuit court in the county in which the personal property is located. State F has conformed state law to federal law to provide that all instruments affecting title to an interest in any civil aircraft of the United States must be recorded in the Office of the Federal Aviation Administrator (FAA) in Oklahoma City, Oklahoma. On July 1, 1990, a tax lien arises against ABC airline, which owns aircraft situated in State F. The Internal Revenue Service files a Notice of Federal Tax Lien with the clerk of the circuit court in the county in which the aircraft is located but does not file the notice with the FAA in Oklahoma City, Oklahoma. Because the FAA system adopted by State F does not constitute a second place of filing pursuant to section 6323(f), the federal tax lien is validly filed.
Example 6. Assume the same facts as Example 5 except that State F did not reenact or conform state law to the FAA requirements. The result is the same because the filing of federal tax liens is governed solely by the Internal Revenue Code, and is not subject to any other national filing system.
26 C.F.R. §301.6323(f)-1