Complete 10-Code List for Truckers

10-4 (affirmative/understood) is by far the most commonly used 10-code in trucking and has become part of everyday American English. The second most common is 10-20 (what is your location?), followed by 10-9 (repeat your last transmission) and 10-7 (out of service/signing off). These four codes make up the vast majority of 10-code usage on CB channel 19.

Not exactly. While the core codes (10-4, 10-9, 10-20) are universal, some 10-codes have different meanings in different regions or between law enforcement and trucking. For example, 10-100 in some systems means 'bathroom break' while in others it means 'civil disturbance.' The APCO standardized list is the most widely accepted, but regional variations exist. When in doubt, use plain language instead of obscure codes.

In law enforcement, yes — many agencies have moved to plain language since the 2001 recommendation by the National Incident Management System (NIMS). In trucking, 10-codes persist as cultural tradition on CB radio, but their daily use has declined. Most truckers today use a mix of the most common 10-codes and plain English. The key codes (10-4, 10-9, 10-20) will likely remain in use for decades due to their embedded cultural status.

Channel 19 is the unofficial but universally recognized trucker highway channel. It is where road condition reports, hazard warnings, and general trucker conversation happen. Channel 9 is the emergency channel (monitored by some law enforcement). Channels 17 and 19 are the most active for truckers. Some regional areas and specific truck stops use other channels for local communication.