9-Code, 10-Code

Over the years, public safety dispatchers have developed a semi-standardized code for speaking on the radio. Although the trend during the past 10 years has been to use plain English for law enforcement and fire communications, many agencies still use codes on the radio. The code is known as "the ten code" because the actual code is preceded by the word "ten." The origin and reason for this is unknown. However, it appears that the "ten" prefix was meant to signal that the numbers following are part of the code, and not an address, age, phone number, etc. Over the years, as more codes were added, the number of ten-codes ran out, and agencies began using "eleven" as a prefix. At some point, other agencies developed a nine-code that accomplished the same thing but used the number nine as a prefix.

The use of codes continues, despite some pressure to use plain English to assist in clarity and operations among different agencies. Once in a while a agency will announce they're switching away from codes. But since many laws, ordinances and other regulations are stated in letter/number codes, many law enforcement agencies continue to use codes over-all.

We do know that the first published 10-Code was in the APCO Bulletin of January, 1940, after a meeting of the State Systems Standards Committee in Springfield (Ill.)--part of their Project 4 to develop developed "Ten Signal Cards." There were only 17 codes in the first version, but it grew to about 60 after the list was first published. APCO also took a stab at standardizing codes back in 1973 as part of their Project 14 to make radio communications more concise. These codes includes those from 10-1 to 10-39, with an "optional" list of codes above 10-39. We don't know of any original listing of these codes on the APCO Web site, but check here for the standard codes, and here for the expanded set.

In late 2005 FEMA established requirements for adoption of the National Incident Management System (NIMS), including a requirement that all public safety agencies routinely use plain English on the radio in order to qualify for any federal grants. However, after some hot debate, FEMA rescinded the order in Feb. 2006, saying plain English was only required when handling multi-agency, multi-jurisdictional incidents. Download (pdf) the explanatory letter.

In early 2009 several large agencies began the transition to plain English, including Dallas PD.

Despite attempts at standardization, there are probably 20 to 30 versions of the original 10-Code being used across the county. Even when an agency uses the standard list, they probably have customized a some of the codes for their own use. For each code we have tried to include the most common definitions. In this consolidated list, some codes have the same definition. Also, many agencies do not use all of the codes on this list, but rather just the few they need.

Many codes can be suffixed by the letter "x" to indicate that a female was involved, or other letters that specify more information ("A" for audible alarm, "S" for silent, etc.).

For this reason, it's not advisable to memorize this list if you intend to study before becoming a dispatcher--your agency probable has its own list. However, it would be helpful to be familiar with the definitions and types of information that are usually condensed to code form.

Also Check

10-0 use caution
10-1 cannot receive you
10-2 receive you OK
10-3 stop transmitting
10-4 OK, I acknowledge, etc.
10-5 relay this transmission
10-6 responding from a distance
10-7 out of service
10-8 available for incidents
10-9 repeat your transmission
10-10 off-duty
10-11 animal incident
10-12 stand-by, hold transmission
10-13 weather/road report
10-14 prowler report
10-15 enroute with arrest
10-16 domestic problem
10-17 out-of-service for fuel
10-18 out-of-service for repairs
10-19 returning to -----
10-20 what's your location? my location is --
10-21 telephone ----
10-22 cancel assignment, disregard
10-23 stand-by, hold transmission
10-24 assignment completed
10-25 meet the person
10-26 person clear of warrants
10-27 driver's license info
10-28 vehicle registration info
10-29 warrant check for person
10-30 improper radio use
10-31 crime in progress
10-32 subject with gun
10-33 alarm sounding, emergency
10-34 riot
10-35 what is time?, major crime alert
10-36 can you copy confidential info?
10-37 suspicious vehicle
10-38 stop suspicious vehicle
10-39 urgent--use lights and siren
10-40 silent response
10-41 beginning tour of duty
10-42 welfare check, ending tour of duty
10-43 information
10-44 permission to leave for
10-45 dead animal at ---
10-46 assist motorist
10-47 emergency road repair
10-48 traffic signal repair
10-49 traffic light out at ---
10-50 accident
10-51 tow truck needed
10-52 ambulance needed
10-53 road blocked at ---
10-54 animals on highway
10-55 security check
10-57 hit-and-run accident
10-58 direct traffic
10-59 escort
10-60 squad in vicinity, lock-out
10-61 personnel in area

10-62 reply to message
10-63 clear to copy info?
10-64 message for delivery
10-65 net message assignment
10-66 net message cancellation
10-67 person calling for help
10-68 dispatch message
10-69 message received
10-70 prowler, fire alarm
10-71 gun involved, advise nature of fire
10-72 shooting, fire progress report
10-73 smoke report
10-74 negative
10-75 in contact with ---
10-76 enroute
10-77 ETA
10-78 need assistance
10-79 bomb threat, coroner's case
10-80 bomb has exploded
10-81 Breathalyzer report
10-82 reserve lodging
10-83 work school crossing at
10-84 if meeting ---, advise ETA
10-85 delay due to ---
10-86 officer on-duty
10-87 pickup
10-88 present phone number of ---
10-89 bomb threat
10-90 bank alarm at ---
10-91 pick up prisoner
10-92 improperly parked vehicle
10-93 blockage
10-94 drag racing
10-95 prisoner/subject in custody
10-96 psych patient
10-97 check signal
10-98 prison/jail break
10-99 wanted/stolen record

11-24 abandoned vehicle
11-25 road obstruction
11-94 pedestrian stop
11-95 vehicle stop
11-96 suspicious vehicle
11-97 security check on officer
11-98 meet at ---
11-99 officer needs help

APCO Alternate (used widely in Texas)

10-1 Signal weak                 10-1 Signal weak
10-2 Signal good                 10-2 Signal good
10-3 Stop transmitting           10-3 Stop transmitting
10-4 Affirmative (yes)           10-4 Acknowledge
10-5 Relay to.....               10-5 Relay to.....
10-10 Negative (no)              10-10 Fight in progress
10-11 Unit on duty               10-11 Dog (animal) call
10-14 Information/msg.           10-14 Prowler