If you’ve ever listened to a couple of veteran truckers having a conversation over CB radio, or police dispatchers barking out orders to coordinate a task, it might sound like a different language.
Part of this language consists of intricate numeric codes called 10-codes, so named because they all start with “10” followed by additional numbers.
It might sound completely impenetrable to outsiders, but that’s only because you don’t know the code.
It’s actually a lot easier to learn yourself with a little bit of practice and repetition, and a great way for you, your group and anyone else communicating on the CB band to save time and reduce ambiguity when the pressure is on.
I’ll be telling you the most useful and commonly used 10-codes in this article. Grab a notepad and let’s get going.
A Note on 10-Code Standardization… Or Lack Thereof
Before we dive right into the list of codes, I just want to make sure that you’re aware of the context in which you should use them.
If you’re just out rolling around I have a CB radio in your vehicle, don’t worry about a thing because most seasoned operators will know these codes and, in any case, if there’s serious trouble most people will probably communicate using plain, spoken language.
Likewise, if you’re talking with any other people in separate vehicles as part of a convoy, or members of your survival group, these codes will suffice just fine.
However, if you’re forced to communicate with law enforcement or emergency services via radio, you might want to think twice: 10 codes were first developed as long ago as the late 1930s, and have been in almost continual use ever since.
In time, according to regional, agency, and even individual departmental preferences, some of the codes came to take on different meanings, and were added to or incorporated into other code systems.
Accordingly, in the mid-2000s federal law enforcement agencies started advocating that 10 codes be dropped in favor of clear, concise language in high-pressure situations.
You’ll have no way of knowing if the agency you’re communicating with is using the exact same 10 codes that you are, and in a time is life situation that could end up costing you seconds or minutes that you just don’t have.
Just something to think about! Now, 10-28 and let’s get to those codes!
10-1
Receiving poorly. Used to indicate to the person talking to you that the message isn’t coming through too well.
10-2
Receiving well. Conversely, used to indicate to the person talking to you that you are reading them loud and clear.
10-3
Stop transmitting. A polite, professional and brief way to tell someone to shut up, or that they might potentially have a stuck transmit button.
10-4
Okay, message received. Confirms to the person sending that you received their message in its entirety. Note that it does not necessarily imply that you will comply, or that you agree.
10-5
Relay message. Gives instructions to the recipient to forward a message to someone else. Rarely used in common conversation, but might be useful in an SHTF situation or when two parties are passing by each other when underway.
10-6
Busy, stand by. Basically tells the listeners that you need a minute until you can get back to the conversation or receive.
10-7
Out of service, off the air. Used to inform listeners that you are either shutting down your radio set, moving out of range or otherwise going to be out of communication via radio.
10-8
In service, ready to receive. Lets listeners know that you are back on the air and able to receive radio traffic.
10-9
Repeat message. Exactly what it says. Asks the person talking to you to repeat their last message or transmission.
10-10
Transmission completed, standing by. Often abbreviated to just 10, by itself. Let’s the listener know that you’re done talking and listening and waiting for their response or additional traffic.
10-11
Talking too rapidly. If someone is being a motor mouth, this lets them know to slow down for following transmissions or messages.
10-12
Visitors present. Lets senders know that you might have other people nearby in case confidential, sensitive or incriminating information will be sent over the air. May also be used to explain going off the air or being available intermittently.
10-13
Advise on conditions. Ask for a status update on weather, traffic or road conditions. Sometimes used more generically to inquire about a status check for an individual or a task.
10-16
Make pickup at (location follows). Exactly what it says, instructs the recipient to make a pickup, of whatever was pre-arranged, at a designated location that is given immediately following the 10-16 code.
10-17
Urgent business. Used to qualify a transmission after issuing a break command on a channel, or when referring more generally to any matters being discussed at the moment.
For instance, the status of someone injured in an accident or after a disaster, or the whereabouts of someone who is sent on an errand of some importance.
10-18
Anything for me/us? A generalized request for tasking or, less often, a request for news or updates on a previously discussed situation or topic. May be used as a reminder if a previous request or pending orders were not delivered.
10-19
Nothing for you, RTB. Used as a response to the previous 10-18 code or a general interrogative, followed by a return to base order. Basically, the day is done, bring it home.
10-20
My location is / where are you? Often abbreviated colloquially as what’s your 20? When used as a response or in an informative manner, you give your location following the code. If used as an interrogative, it is asking for the location of the person you are talking to?
10-21
Call by telephone. Simply a request for the recipient to call the sender via telephone instead of continuing the conversation via CB.
10-22
Report in person to (location or individual). Instructions for the recipient to report to or check in bodily at a location or with a designated individual, agency, or other body.
10-23
Standby. Wait a moment or wait for instructions…
10-24
Completed last assignment. Used to check in with a dispatcher, agent, or anyone else and let them know that the current tasking has been completed.
10-25
Can you contact (person/entity)? A request for the recipient to contact a designated person or entity either on behalf of the sender or for some other reason. If context is not previously discussed, make sure you explain the reason for the contact request.
10-26
Disregard Last/Ignore Last/Cancel. A blanket code that instructs the recipient to ignore, disregard, delay or otherwise cancel the previous code or transmission.
10-27
I am going to channel (frequency or channel). Informs the recipient that the sender is switching channels or frequencies. If not previously discussed or given a code word, make sure you let the recipient know which channel you’re going to.
10-28
Identify your station. A request for the sender to name and identify their station.
10-29
Time is up for contact. Used as a warning to the person you are talking to or anyone else who might need to transmit to you that you no longer have time to speak due to circumstances, events or other tasks.
10-30
Does not conform to FCC rules. This is basically tattle-tailing and letting whoever is currently breaking FCC rules know that you know the rules and that they should stop doing whatever they are doing.
Often threatened to gain compliance over reckless, rude, or inconsiderate CB users. That said, don’t be a narc…
10-32
I will give you a radio check. Used when someone asks for a radio check or indicates that they are having trouble with their set.
10-33
Emergency traffic at the station. Used to let anyone on the channel know that the sender is experiencing emergency traffic at or near their location. This could indicate police, fire, paramedics, etc. or civilian traffic.
10-34
Trouble at this station, help needed. Indicates that there is something going wrong or an emergency at the sender’s location and that anyone receiving should converge and attempt to render aid…
10-35
Confidential information. It means that the person inquiring does not need to know whatever it is they are asking for. Also a reasonably polite, but brusque, way to tell someone to mind their own business.
10-36
Correct time is (time call). Used to let the person asking for an accurate time call know what the time is.
10-38
Ambulance needed at (location). A request for help or notification that someone is injured and medics are needed. Basically, call an ambulance and send it to the indicated spot!
10-39
Your message delivered. Used to let someone who issued a 10-5 know that the message was delivered to the recipient.
10-41
Please tune to channel (channel no.). Lets anyone listening or the person receiving know that they should tune their radio to the indicated channel following the code.
10-42
Traffic accident at (location). An update that will let anyone listening know there has been some kind of accident on the road at the location following the code.
10-43
Traffic slowdown/stoppage at (location). This code lets anyone listening know that there is heavy traffic, major slowdown or even a traffic stoppage at the location following the code.
10-44
I have a message for you (or for someone else that you can pass on). Lets the recipient know that a message will be following that is intended for them or for someone else that they need to pass on as indicated.
10-45
All units within range please report. Asks for a check-in for everyone in a group or that is receiving the call.
10-50
Break channel. This code is used to issue a break, meaning that everyone talking on the channel should shut up at once. Typically precedes urgent information.
10-62
Unable to copy, use phone. Wants the recipient to know that, for whatever reason, the person issuing the code can’t hear them or the message isn’t getting through, and to call them via telephone.
10-62sl
An unofficial but common code that lets the recipient know the sender is unable to copy on am and to use sideband lower.
10-62su
A corresponding unofficial but still common code that lets the recipient know the person issuing the code cannot copy and to use sideband upper.
10-65
Awaiting next message or task. Let’s dispatch, agent or base station know that you are basically twiddling your thumbs and ready for work.
10-67
All units comply. When issuing a mass order, update or status change asks for confirmation and acknowledgment from everyone in a group or everyone receiving on the channel.
10-70
Fire at (location). Just what it says, lets all hearers know that there is a fire at the location following the code.
10-73
Speed trap at (location). Let’s all hearers know that there is a speed trap set up at the location following the code. It’s a good idea to give details on the type and nature of the trap. See also, “the bears are hungry.”
10-75
You are causing interference. Lets the recipient of the message know that they are causing electronic interference or interfering with an ongoing conversation.
10-77
Negative contact. A status update that lets a person know that the sender was unable to make contact with someone or that the contact was uneventful.
10-84
My telephone number is (followed by number). Used to let a recipient know what your phone number is so they may call or text you on it. Just a reminder, absolutely anyone can tune in to CB radio communications, so don’t throw your phone number around lightly.
10-85
My address is (followed by address). Exactly what it says. Again, do not be too quick to splash around your personal information on CB radio. There’s no telling who might be listening, or how many people might be.
10-91
Talk closer to the mic. Used to let someone know that they are muffled, or that the mic is too far away from their mouth and they are coming through a little soft.
10-92
Your transmitter is out of adjustment. A generalized request that someone check their equipment and try again.
10-94
Please give me a long count. Exactly what it says. Request that the recipient give the sender a long count.
10-95
Transmit dead carrier signal for 5 seconds. Asks that the recipient key the mic but say nothing for 5 seconds.
10-99
Mission complete, all units secure. Typically issued by a person in charge of a multi-man operation or coordinated task. Lets all participants know that the deed is done and all participants are accounted for.
10-100
Need to go to the bathroom. Self explanatory. This one is especially useful in multi-vehicle or convoy operations.
10-200
Police needed at (location). Exactly what it says. Asks that any hearers summon and dispatch police to the indicated location following the code.
Tom Marlowe practically grew up with a gun in his hand, and has held all kinds of jobs in the gun industry: range safety, sales, instruction and consulting, Tom has the experience to help civilian shooters figure out what will work best for them.