4 U.S. Code § 120
4 U.S. Code § 120 is about Procedure if no electronic database provided. It is under Chapter 4 (The States) of Title 4 (Flag And Seal, Seat Of Government, And The States) of the Code.
(a) Safe Harbor.—If neither a State nor designated database provider provides an electronic database under section 119, a home service provider shall be held harmless from any tax, charge, or fee liability in such State that otherwise would be due solely as a result of an assignment of a street address to an incorrect taxing jurisdiction if, subject to section 121, the home service provider employs an enhanced zip code to assign each street address to a specific taxing jurisdiction for each level of taxing jurisdiction and exercises due diligence at each level of taxing jurisdiction to ensure that each such street address is assigned to the correct taxing jurisdiction. If an enhanced zip code overlaps boundaries of taxing jurisdictions of the same level, the home service provider must designate one specific jurisdiction within such enhanced zip code for use in taxing the activity for such enhanced zip code for each level of taxing jurisdiction. Any enhanced zip code assignment changed in accordance with section 121 is deemed to be in compliance with this section. For purposes of this section, there is a rebuttable presumption that a home service provider has exercised due diligence if such home service provider demonstrates that it has—