Electronic Communications Privacy Act, Title III (Pen Register and Trap and Trace Devices)
Pen Register Act
Communications
The Pen Register Act bars installing or using devices that capture non-content routing and addressing information (such as numbers dialed or email headers) without a court order, subject to provider exceptions. It is primarily a limit on government surveillance but also reaches private parties.
- Where
- Federal
- Citation
- 18 U.S.C. 3121-3127
- Status
- In force
- In force since
- 1987-01-19
- Last amended
- 2018-03-23
- Enforced by
- U.S. Department of Justice
- People can sue
- No
- Penalties
- Knowing violation is a misdemeanor punishable by fine and up to one year in prison.
- Applies to
- Any person installing or using a pen register or trap and trace device (dialing, routing, addressing, and signaling information)
- Providers of wire or electronic communication services
Practices it requires
- Do not install or use a pen register or trap and trace device without a court order, except for listed provider purposes or with user consent.18 U.S.C. 3121(a)-(b)
- Providers assisting under an order must not disclose the existence of the device or investigation unless the court orders otherwise.18 U.S.C. 3123(d)
Sources
Checked against these sources on 2026-09-25 by research agent (Claude), primary sources.
Research reference, not legal advice.