Are Faraday Bags Legal in the U.S.? Yes — Here's What You Actually Need to Know

Q: Why does this question come up so often?

Two reasons. (1) The technology sounds adversarial — 'blocking signals' triggers a legality reflex even though microwave-oven doors and Mylar emergency blankets do the same thing. (2) Active signal jammers ARE illegal under 47 CFR § 2.803, and product confusion between active jammers and passive Faraday bags drives the question. They're different legal categories. Faraday bags transmit nothing; the FCC has no jurisdiction.

Operational Details

The technology is in standard government use.

U.S. States Legal

Federal Permits Required

FBI

Issues as Standard Kit

NIST

SP 800-101 Endorsed

Trusted by Operators

Law-enforcement evidence handling. SOC teams. M&A counsel desks. Family-office security staff.

The technology used by federal forensic labs to preserve chain-of-custody on seized phones is the same passive-shielding category sold to civilians. NIST SP 800-101 (Mobile Device Forensics) explicitly recommends Faraday isolation. That endorsement is dispositive — a technology used as evidence-handling equipment by federal law enforcement is not contraband.

The Five Exceptions

Where it gets nuanced — and why it doesn't matter for 97% of the time you'd actually carry one.

Your principal's MacBook is on hotel WiFi. The valet has the key fob. Your iPhone just connected to "Marriott_Guest" — except the real Marriott_Guest network is two floors up, and the SSID broadcasting in the parking garage isn't theirs. None of this is hypothetical. None of this is rare. And none of the five legal restrictions below apply to a single one of those moments.

U.S. courthouses

Phones surrendered or powered off at security regardless of bag. The bag isn't restricted; the device is.

Federal SCIFs (FBI, DoD, IC)

Devices left at a facility-issued check-in station. Personal Faraday bags don't substitute.

Correctional facilities

Visitor entry prohibits Faraday bags (potential contraband-smuggling vector). Leave it in the car.

Polygraph rooms

All electronics out of room. Bag and contents stay outside for the exam.

Active TSA screening

Electronics out for separate X-ray; bag passes after agent verifies normal contents (1–3 min secondary inspection on first trip).

Critical Distinction

The one thing that is illegal — and isn't a Faraday bag.

Active signal jamming (devices that transmit to disrupt nearby communications) is illegal under 47 U.S.C. § 333 with civil penalties up to $112,500 per violation. The FCC enforces it. Passive shielding — Faraday bags, RF wallets, isolation pouches — transmits nothing, has no FCC jurisdiction, and is unaffected by that law.

If a product description says "jam" or "actively block transmissions," that's a different legal category from a Faraday bag. A Faraday bag shields only what's inside it, only while it's inside. Microwave-oven doors and Mylar emergency blankets work the same way — and have never been regulated.

FAQ

The questions everyone asks first.

Are Faraday bags legal in all 50 U.S. states?

Yes. No federal license, no state permit, no registration. Civilians, executives, attorneys, family-office staff, and law-enforcement personnel may purchase and use them everywhere in the United States. The FBI, DEA, and CBP issue them as standard equipment — that official endorsement settles the question.

Can I bring a Faraday bag through TSA?

Yes. The bag itself is unrestricted. Electronics inside (laptop, phone, tablet) come out for separate screening like any other carry-on. The metallized lining looks opaque on X-ray — expect a possible secondary inspection on first-time travel, resolves in under two minutes once the agent verifies normal contents.

What about courthouses, federal buildings, or prisons?

Five specific settings restrict device-handling: courthouses (phones surrendered regardless of bag), federal SCIFs (devices left at check-in), correctional facilities (no Faraday bags through visitor entry), polygraph rooms (electronics out of room), and active TSA screening. The bag itself remains lawful to own; entry rules govern facility-specific use.

Is blocking AirTag, GPS, or cellular signals legal?

Yes — under U.S. law you have no obligation to broadcast your location. Faraday-blocking signals from your own devices is fully legal. Blocking signals from a tracker someone placed on you without consent is also legal — and the placement itself may be a federal crime under 18 U.S.C. § 2261A. Critical distinction: passive shielding (Faraday bag, always legal) is a different legal category from active jamming (transmits, illegal under 47 U.S.C. § 333).

Can businesses provide Faraday bags to employees?

Yes — and increasingly required by corporate-security policy. Finance firms, M&A counsel, healthcare-compliance teams, and intelligence-sensitive industries issue them as standard equipment. Custom-branded bulk procurement for EP firms and SOC teams is routine. The REVIS-1 /business program supports custom-branded U.S.-made bulk orders with net-30 invoicing.

Why does this question come up so often?

Two reasons. (1) The technology sounds adversarial — "blocking signals" triggers a legality reflex even though microwave-oven doors and Mylar emergency blankets do the same thing. (2) Active signal jammers ARE illegal under 47 CFR § 2.803, and product confusion between active jammers and passive Faraday bags drives the question. They're different legal categories. Faraday bags transmit nothing; the FCC has no jurisdiction.

Yes. Legal in all 50 states. The threat actor is hoping you don't know that.

The technology is in standard government use.

Law-enforcement evidence handling. SOC teams. M&A counsel desks. Family-office security staff.

Where it gets nuanced — and why it doesn't matter for 97% of the time you'd actually carry one.

The one thing that is illegal — and isn't a Faraday bag.

Carry quietly. Move freely.

The questions everyone asks first.

Carry everything.