CB Radio 10-Codes: The Complete List (Plus What Truckers Actually Say in 2026)

10-4 means “message received” — the most famous CB 10-code, but there are 34 official codes used across CB, police, and trucking radio.

Ten-codes, also called ten signals, are short radio phrases built to make common messages faster to say. They began in public-safety radio and became part of CB culture, especially on the highway. The historical ten-code reference also makes an important point: the same number can mean different things in different agencies, regions, and eras.

For CB use, the practical answer is simple: know the handful you will hear most, keep this reference handy for the rest, and use plain English whenever a message needs to be unmistakable.

CB 10-codes: the 10 you will hear most

Need the quick version? These are the ten codes worth memorizing first:

• 10-1 — Poor reception.
• 10-4 — Message received / OK.
• 10-7 — Out of service (off air).
• 10-8 — In service (back on air).
• 10-9 — Repeat message.
• 10-10 — Standing by / transmission done.
• 10-20 — “What’s your location?”
• 10-33 — Emergency traffic.
• 10-36 — Correct time.
• 10-100 — Personal comfort stop (bathroom).

The complete CB 10-codes list

The table below follows the traditional CB codebook used by many radio references. It is a practical CB reference—not a promise that every police department or local group uses the same meanings. Public-safety agencies have long used different versions of ten-codes, and APCO has supported plain speech for public-safety communication to reduce confusion.

Source note: CB lists commonly use the meanings above; compare Firestik’s CB 10-code reference and President Electronics’ CB guide. For historical APCO versions and the many regional variations, see Wikipedia’s ten-code history.

What people actually say vs. the codebook

You do not need to sound like a 1970s movie convoy to communicate well. On a busy channel, short plain-English calls are normal. The codebook is useful context, but clarity matters more—especially when traffic, weather, or an emergency is involved.

• “10-4” usually means “got it,” “yes,” or “I agree.”
• “What’s your 20?” is the everyday way to ask someone’s location.
• “Come back” means “respond when you can.”
• “Read you loud and clear” means your signal is understandable—essentially the idea behind 10-2.
• “Radio check” is more likely than a formal 10-32.
• “Break 19” or “breaker one-nine” asks to join the conversation on Channel 19.

Trucker slang beyond 10-codes

CB slang changes by region and by generation. These terms are still useful to recognize on the road, even when the conversation is mostly plain English.

How to actually use 10-codes on Channel 19

On Channel 19, most modern drivers simply say what they mean: “Brake lights ahead,” “left lane is closed,” or “there’s a backup at mile marker 42.” That is often faster and clearer than turning every message into a code.

The exceptions are the familiar ones. 10-4, 10-20, and 10-33 are widely understood. If a message is urgent, say it plainly first, give your location, and keep the channel clear. Channel 19 is the traditional trucker channel, while Channel 9 is reserved for emergency communication.

CB channels people confuse with 10-codes

Channels and ten-codes solve different problems: a channel tells you where to listen, while a ten-code is a short way to say what you mean. Channel 9 is the emergency channel; Channel 19 is the well-known trucker channel. Many drivers also associate Channel 17 with California highway traffic and call Channel 6 “the Super Bowl.”

Want the frequencies and a fuller channel-by-channel explanation? Read our CB radio frequencies and channels guide.

The gear you need to actually hear 10-codes clearly

A useful code is no help if the audio is muddy. Start with a CB that has a clear, capable speaker, such as the Cobra 29 LX or the Uniden Bearcat 880. Both make strong choices for drivers who want a straightforward, easy-to-hear mobile radio.

Just as important, use a properly installed and tuned antenna. Our guide to the top CB antennas for maximum range can help you choose the right setup. For an additional paid checkout option, a bench peak-and-tune can help optimize radio performance and may improve receive sensitivity in the right setup; it is not included with the radio.

CB 10-codes FAQ

What does 10-4 mean on a CB radio?

10-4 means “message received,” “OK,” or “understood.” It is the best-known CB ten-code and is still common in everyday speech.

What is a 10-20 in CB slang?

A 10-20 is a location. “What’s your 20?” means “Where are you?”

Are 10-codes still used in 2026?

Yes, but selectively. 10-4, 10-9, 10-20, and 10-33 remain familiar to many CB users, while most drivers use plain English for the rest of the conversation.

What’s the difference between CB 10-codes and police 10-codes?

They share history, but they are not one universal codebook. Police agencies may assign different meanings to the same number, while CB users tend to follow traditional CB meanings. For emergencies, clear plain English is the safer choice.

What is 10-100 in CB radio?

10-100 means a personal comfort stop—a bathroom or restroom break.

What channel do truckers use?

Channel 19 is the traditional trucker channel and the most common place to hear road and traffic talk.

Is Channel 9 really the emergency channel?

Yes. Channel 9 is the designated CB emergency channel. Keep it open for emergencies and use another channel for routine conversation.