Ten-codes, properly known as ten signals, are code words used to represent common phrases in voice communication, particularly in radio transmissions. The codes, developed in 1937 and expanded in 1974 by the Association of Public Safety Communication Officials, allow for brevity and standardization of message traffic. They are widely used by law enforcement officers in North America. Ten-codes were also adapted for use by CB radio enthusiasts before its pop culture explosion in the late 1970s, thus many of the phrases, such as 10-4 and "what's your twenty" have entered everyday use in the English language.
Some municipalities also use signal codes (e.g. "Code ten"), which typically gives further information the nature of a crime or emergency. These vary drastically from agency to agency.
List of 10-codes
The following list illustrates the current usage of various 10-codes. Only a handful of them are standardized. Some are fairly consistent, while others (such as 10-40) can have completely different meanings, many of which are not listed here. Multiple meanings for the same code are set apart by semicolons. Those definitions that have been adapted by most law enforcement agencies are set in bold. Meanings specific to CB radio are set in italics. This is not a complete list, but is intended to show some of the most common codes and help provide an estimate of what a code's definition is; a search for local ten-code tables should be performed first before using this chart.
- 10-0 use caution
- 10-1 poor reception
- 10-2 good reception
- 10-3 stop transmitting
- 10-4 message received, affirmative, ok
- 10-5 relay this information to ___
- 10-6 busy
- 10-7 out of service
- 10-8 in service
- 10-9 please repeat your message
- 10-10 out of service; negative; transmission completed; fight in progress; welfare check
- 10-11 talking too fast; enroute; animal check
- 10-12 visitors present; standby ; disregard; call in reports; at scene; check revocation
- 10-13 advise weather/road conditions, civilians present and listening; call-in resume
- 10-14 convoy or escort; suspicious person or prowler
- 10-15 prisoner/suspect in custody; domestic disturbance
- 10-16 domestic disturbance; make pickup at ___
- 10-17 meet complainant; pick up papers at ___; urgent business
- 10-18 urgent; complete assignment ASAP; anything for us?; drunk
- 10-19 return to station
- 10-20 specify ___location/my ___location is ___
- 10-21 please telephone ___
- 10-22 disregard; report to ___; send blood technician
- 10-23 stand by on this frequency; arrived at ___location/on scene; status check; enroute to call; sex offense
- 10-24 assignment completed; trouble at station; unit not available; direct traffic
- 10-25 please contact person; do you have contact with person; come in for traffic; officer needs help
- 10-26 detaining suspect, expedite;; check auto registration; ETA; disregard last info; phone residence
- 10-27 drivers license request; vehicle registration request; I am moving to channel ___; any answer
- 10-28 vehicle registration request; driver's license request; identify your station; missing person
- 10-29 arrests/warrants request; time is up for contact
- 10-30 inappropriate use of radio; danger/caution; special check at ___; juvenile
- 10-31 crime in progress; domestic disturbance; check for local warrants; suspicious person
- 10-32 person with gun; fight in progress; radio check; check NCIC; DWI test
- 10-33 emergency traffic follows, hold routine messages; officer needs help; disturbance at ___; fire
- 10-34 frequency open (cancels 10-33); help needed; riot; trouble at jail; correct time; meet officer
- 10-35 confidential information; major crime alert; supicious person
- 10-36 correct time of day?
- 10-37 identify yourself; wrecker needed at ___; suspicious vehicle; shoplifter
- 10-38 ambulance needed; stopping suspicious vehicle; station report satisfactory; phone communications; vandalism
- 10-39 your message was delivered; false alarm, premises were occupied; run with lights; contact officer; disturbance
- 10-40 false alarm, no activity, premises appears secure; please tune to channel ___; expedite; run silent; advise if available; suspicious person; dead animal; mental patient; lunch
- 10-41 begin duty; radio test; intoxicated person; debris in street; neighbor trouble
- 10-42 end duty; traffic accident at ___; malicious mischief; request dispatch times
- 10-43 traffic jam at ___; request criminal history; information; pick up passenger; armed robbery; rescue call
- 10-44 I have a message for you; permission to leave; transmission received; rape; traffic accident (no injury)
- 10-45 pick up officer; fueling vehicle; all units in range please report; animal carcass; coffee break; traffic accident (injury)
- 10-46 motorist assist; lunch break; fuel break; wrecker
- 10-47 emergency road repair; call home; missing person; drunk driver; blood run
- 10-48 traffic light repair; request criminal history; runaway juvenile; use caution
- 10-49 en route to assignment; traffic light out; bathroom break; any traffic; serving warrant
- 10-50 accident; no messages; break channel; auto accident with property damage
- 10-51 wrecker needed; auto accident with injuries; phone message
- 10-52 ambulance needed; fatal auto accident; message for assignment; alarm
- 10-53 road blocked; silent alarm
- 10-54 animals on highway; silent pursuit; car stop
- 10-55 intoxicated driver; security check; ambulance call
- 10-56 intoxicated pedestrian; warrant indicated; arrived at scene
- 10-57 hit-and-run accident; narcotics; officer at pistol range
- 10-58 direct traffic; wrecker; DOA; teleprinter message
- 10-59 escort; out of car checking violation; ambulance; bomb threat
- 10-60 traffic stop; squad in vicinity, lock-out; what is next message number?; coffee break; assist motorist
- 10-61 personnel in area; stand by for CW traffic; clear of traffic stop; weather conditions?; lunch break
- 10-62 reply to message; unable to copy, use phone; check for rising water; logged on/off
- 10-63 clear to copy info?; net directed to ___; need barricades
- 10-64 message for delivery; net clear, resume normal traffic; field investigator
- 10-65 net message assignment; kidnapping
- 10-66 net message cancellation; bathroom break
- 10-67 prepare to copy; person calling for help; all units comply
- 10-68 dispatch message; repeat dispatch; switch channels
- 10-69 message received; any calls holding for me?; sniper
- 10-70 prowler, fire alarm; fire; fire followup; net message; chemical spill
- 10-71 gun involved; advise nature of fire; proceed with transmission; officer needs assistance; fire inspector
- 10-72 shooting; fire progress report; check safety of officer; follow-up rescue; radar assignment; street blocked
- 10-73 advise current status; smoke report; speed trap at ___; notify coroner; arson investigation
- 10-74 negative; tactical plan
- 10-75 in contact with ___; you are causing interference; drunk driver; miscellaneous out code
- 10-76 en route; traffic accident; send SWAT team
- 10-77 ETA ___; negative contact; accident with injury
- 10-78 need assistance; major accident with injury; request wrecker
- 10-79 notify coroner; bomb threat; hit & run
- 10-80 bomb has exploded; pursuit in progress; tower lights out; on assignment; demonstration
- 10-81 breathalyzer request; stop for interrogation; reserve hotel room; officer ___ will be at your station; at vehicle maintenance; civil disturbance/riot
- 10-82 reserve lodging; stop for interrogation/arrest; traffic signal out; cover assistance
- 10-83 work/school crossing at ___; call station; units stop transmitting; at radio shop; officer in trouble
- 10-84 if meeting ___, advise ETA; checking officer status; my telephone number is ___; follow-up; broken utility main
- 10-85 delay due to ___; prepare to copy info; my address is ___; loose livestock
- 10-86 officer on-duty; utility line down
- 10-87 pickup or prisoner transfer; dead body
- 10-88 telephone number of ___; station call; special assignment; true alarm
- 10-89 bomb threat; send radio repair; officer at academy
- 10-90 alarm; radio repair to be at station; officer at headquarters; false alarm
- 10-91 pick up prisoner; talk closer to the mike__; prepare your inspection; vehicle fuel
- 10-92 parking violation; your signal is weak; officer at court
- 10-93 blockage; please check my frequency
- 10-94 drag racing; give me a long count
- 10-95 prisoner/suspect in custody; transmit dead carrier for 5 seconds
- 10-96 psych patient
- 10-97 arriving at scene; test signal; possible wanted person in vehicle; known offender; officer at court
- 10-98 criminal history indicated; prison/jail break; officer at juvenile court
- 10-99 warrants/stolen indicated; officer needs assistance/held hostage; mission complete; bathroom break
- 10-100 bathroom break; dead body
- 10-200 police needed