Register it. The federal rule that governs consumer cell boosters makes two things conditions of running one: your carrier’s consent, and registering the device with that carrier. It is 47 CFR 20.21, read on Cornell’s Legal Information Institute on August 13, 2026, and the requirement is not buried. It is the first two items in the list.
Subsection (a) puts the whole burden on the person operating the booster: obtain the consent of the licensee providing service, register the booster with that licensee, operate only with the antennas and cables the manufacturer approved, and, for a wideband booster, use it for personal use only.
The box tells you too
Most people never read the rule, but they have read the label without noticing. Subsection (f) prescribes the wording, and it has to appear in the manual, on the packaging, in online point-of-sale material, and on the device: “BEFORE USE, you MUST REGISTER THIS DEVICE with your wireless provider and have your provider’s consent.”
The same label carries the part that gets skipped: “You MUST cease operating this device immediately if requested by the FCC or a licensed wireless service provider.” A booster is a transmitter. If it starts stepping on a network, the carrier can tell you to shut it off, and the label is your notice that they can.
Two other lines on that label are worth your attention in a rig. E911 location information may not be provided or may be inaccurate through a booster, which matters more when you are the far side of a forest road than it does in a suburb. And the antennas are meant to be kept at least 20 cm from any person, which is a real constraint in a van, where the inside antenna usually ends up wherever there was space rather than wherever it belongs.
What registration actually costs
Nothing, by rule. Subsection (h) requires each carrier to run a free registration mechanism and to collect at minimum the owner’s name, the make, model and serial number, the location of the device, and the date of initial operation. Verizon’s page, checked August 13, 2026, states plainly that there is no fee to register or use a booster. T-Mobile’s page, same date, asks for your account number and device details.
Here is the awkward part, and we would rather name it than paper over it. “The location of the device” is an address field written for a house. A booster in a truck moves every few days, 20.21 does not carve out an exception for that, and neither carrier page we opened tells a traveling subscriber what to enter. We could not open the FCC’s own consumer guide to check its wording, since fcc.gov returned a 403 to us on August 13, 2026, so we are not going to invent the agency’s position. Ask your carrier when you register and go with the answer they give you.
None of this changes what the hardware can do, which is amplify a weak signal, not create one where there is none. That is covered in what a booster actually does, and the coverage guide covers picking where to sit in the first place.