CB stands for Citizens Band. It's a license-free, two-way radio service with 40 shared channels between 26.965 and 27.405 MHz, limited to 4 watts on AM or FM and 12 watts on single sideband. Anyone eligible can buy a certified CB and talk the same day. Since 1983 there has been no license to apply for.
The FCC's definition, from 47 CFR 95.903: "A mobile and fixed two-way voice communication service for facilitating personal, business or voluntary public service activities, including communications to provide assistance to highway travelers."
How we checked this
We read 47 CFR Part 95, Subparts A and D, in the eCFR on October 21, 2026 (the eCFR shows Title 47 up to date as of October 19, 2026), and the FCC's Citizens Band Radio Service page the same day. Every rule below links to its section. History comes from Wikipedia's Citizens band radio article and Cobra's support pages, and we say so where we use it.
"How we pick" is our label for research from official sources and product listings. Nothing on this page comes from a field test. How we research.
CB in one table
| Question | Answer | Source |
|---|---|---|
| Band | HF, 26.965 to 27.405 MHz (the "11-meter" band) | 95.963 |
| Channels | 40, each 10 kHz wide, shared by everyone | 95.963, FCC CB page |
| License | None; licensed by rule | 95.305 |
| Who can operate | Anyone, any age, except foreign governments, federal agencies and people under an FCC cease-and-desist order | 95.305(c)-(d), FCC CB page |
| Power | 4 W carrier on AM or FM; 12 W peak envelope power on SSB | 95.967 |
| Modes | AM or SSB, and FM may be added (FM since 2021) | 95.971 |
| Amplifiers | Prohibited, no exceptions | 95.939 |
| Emergency channel | Channel 9, emergencies and traveler assistance only | 95.931(a)(2) |
| Talk time | 5 minutes per conversation, then 1 minute off that channel | 95.957 |
| Antenna height | On a structure: 60 ft above ground, or 20 ft above the building or tree it's on, whichever is higher. No limit for vehicles or handhelds | 95.941, FCC CB page |
| Contacts abroad | Not allowed, except Canada's General Radio Service | 95.933(d) |
| Call sign | None; you may use a "handle" of your choosing | FCC CB page |
How CB radio works
A CB radio is a transceiver: one box that both transmits and receives. You pick a channel, listen, then press the mic button to talk. While you hold the button you can't hear anyone, so conversations go back and forth one at a time, which is where "over" and "come back" come from. Everyone in range on that channel hears you. There's no privacy and no addressing; the channel is a party line.
Most CB traffic is AM, the same kind of signal as AM broadcast radio. It's simple and every CB has it, but it picks up engine and static noise. Single sideband (SSB) radios squeeze the signal into a narrower slice and are allowed 12 watts peak, so they carry farther through noise, but both ends need an SSB radio. FM became legal on CB in 2021 (the eCFR notes for 95.967 and 95.971 cite 86 FR 53565, Sept. 28, 2021), and it sounds cleaner, though an AM radio can't properly hear an FM signal.
At 27 MHz the wavelength is about 11 meters, which is why antennas are long. A full quarter-wave antenna is roughly 9 feet, the reason truckers run 102-inch steel whips. That long wavelength also lets CB signals sometimes bounce off the ionosphere and land hundreds of miles away, which CB users call skip.
How far a CB reaches day to day depends mostly on the antenna and its height. Our CB radio range guide works through the numbers, handheld to base station.
Where CB came from
The FCC set up its first citizens radio service in 1945. The 27 MHz service people now call CB arrived as "Class D" in 1958 with 23 channels; Cobra's support page also dates CB to 1958. The 1970s made it a national fad, helped along by movies and music, and the band grew to 40 channels in 1977. According to Wikipedia's account, which cites the New York Times, the FCC stopped requiring individual CB licenses on April 28, 1983.
Two later changes still trip people up. The FCC's 2017 rewrite of Part 95 dropped the old ban on contacting stations more than 155.3 miles away, as ARRL reported, so "shooting skip" to another state is now legal (talking to other countries still isn't, apart from Canada). And FM joined AM and SSB in 2021.
Do you need a license for CB?
No. The FCC's CB page says it plainly: "An individual license is not required to operate a CB station and the FCC does not renew formerly issued CB Radio Service licenses." The legal basis is 95.305, which authorizes eligible people to run Personal Radio Service stations "without individual licenses" unless a service's own rules require one. CB's rules don't.
"Licensed by rule" still means rules. Two conditions matter most:
- The radio has to be FCC-certified for CB (95.335). A ham radio or a "10-meter export" radio that tunes 27 MHz isn't a CB, and using one on CB channels is unauthorized operation (95.935).
- Break the operating rules and your authority to use CB without a license is void (95.905).
There's no call sign to look up, either. The FCC lets you use any on-air nickname, the "handle." The rest of the vocabulary, from "breaker" to "10-4," is in radio lingo and 10-codes.
Are CB amplifiers legal?
No, and the rule is unusually blunt. 47 CFR 95.939: "The operator of a CBRS station must not use an external radio frequency power amplifier to increase the transmitting power of that CBRS station under any circumstances. There are no exceptions to this rule."
The FCC also presumes you used one if an amplifier is in your possession or on your premises and there's other evidence your station ran above the 4-watt or 12-watt limits (95.939(a)). Selling an amplifier intended for CB is banned separately (95.991(a)), and so is modifying a CB for more power or extra frequencies (95.337).
If you want more reach legally, the antenna is where it comes from. A better antenna works in both directions: it sends more of your 4 watts out and pulls in weaker stations, while an amplifier only boosts what you send. Our CB antenna guide covers the options.
Channel 9, channel 19 and the rest
Only one channel has a legal job. 95.931(a)(2): "CBRS Channel 9 may be used only for emergency communications or traveler assistance. It must not be used for any other purpose." Any channel may carry an emergency call, and emergency traffic has priority on all of them.
Channel 19 (27.185 MHz) is where truckers talk, by custom. SSB users gather on 36 through 40, and many off-road groups use channel 4; those are habits too. The full chart with every frequency is on our CB channels and frequencies page.
Who uses CB now
Long-haul truckers are still the core: road reports, weigh station news and finding a parking spot on 19. Farm crews use it field to field, off-road clubs use it on trails, and it shows up in emergency kits because it needs no license, no cell signal and no infrastructure.
CB is one of four common choices. GMRS needs a $35 license but gives clearer audio, short antennas and repeaters; FRS is license-free walkie-talkies; ham radio needs an exam and opens far more bands. Our GMRS vs FRS vs CB vs ham comparison lays them out side by side, and what GMRS radio is covers CB's licensed cousin.
Getting on the air
A first CB station is three things: a certified radio, a proper antenna and a tuned connection between them. For a truck, the Cobra 29 LTD Classic is the long-running favorite and the top seller in our check; the compact Uniden PRO520XL fits small cabs; and the Uniden Bearcat 980 adds SSB. Our best CB radio guide compares them, and if you want something portable, see the best handheld CB radios. Once it's installed, set the squelch and RF gain before you judge how well it works.
Sources: eCFR 47 CFR Part 95 (Title 47 up to date as of October 19, 2026): 95.305 · 95.335 · 95.337 · 95.903 · 95.905 · 95.931 · 95.933 · 95.935 · 95.939 · 95.941 · 95.957 · 95.963 · 95.967 · 95.971 · 95.991. FCC Citizens Band Radio Service page. History: Wikipedia, Citizens band radio; Cobra, "What is CB?"; ARRL (2017 rules). Rules checked: October 21, 2026. How we research · Affiliate disclosure