pen register


pen reg·​is·​ter
: a device that registers the numbers dialed from a telephone compare wiretap

Note: A court order is always required for the use of a pen register in a criminal investigation, but such use has not been considered a search or interception of communication by the U.S. Supreme Court. Some states have disagreed and discern a privacy interest in such information.

Word History


perhaps from the original use of a pen to mark the dots or dashes used in counting the numbers dialed

Dictionary Entries Near pen register

Cite this Entry

“Pen register.” Legal Dictionary, Merriam-Webster, Accessed 16 Jul. 2024.

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