The part follows the classification of the parent machine. If the cash register is classified as an ADP machine (group 752), its parts should be classified under the ADP parts headings rather than here. If the register is classified as a cash register incorporating a calculating device, this heading applies. Resolving the parent machine's classification — ideally through a binding ruling — is the prerequisite step.

Postage-franking machines are regulated by postal authorities in their country of use, and replacement parts may need to comply with device-specific approval requirements set by the US Postal Service or the manufacturer's certification program. While customs entry itself follows standard procedures, importers should verify that replacement components meet any applicable postal regulatory standards before installation.