Taximeters must receive type approval from the applicable state or local weights-and-measures authority — and in some cities, from a municipal taxi commission — before installation in a licensed for-hire vehicle. NIST Handbook 44 provides the national model standard for taximeters, but enforcement and approval procedures vary by jurisdiction. Importers and fleet operators should identify the approval authority for each target market and obtain type-approval documentation from the foreign manufacturer prior to procurement.

A standalone odometer imported as a separate aftermarket replacement part is classified under this heading. An odometer that is physically integrated into a complete instrument cluster or dashboard assembly is generally classified with the cluster as a whole, under the heading applicable to vehicle instruments or parts. The determining factor is whether the odometer arrives as a discrete, separately presented article or as a component of a larger assembly.