The Most Common
Police 10 Codes

-- Introduction
-- 10 Code List
-- Police Scanners

Ten (10) codes are used to communicate efficiently for radio transmissions. The word ten (10) indicates the next number, or numbers, is a code message. The codes are used extensively by police, fire, medical (ground, air, and hospitals), public services, businesses (taxi's etc) and individuals (Citizen Band radio, walkie-talkies).

There are six code messages (universal) used by most code versions.

10-4 -- Acknowledge
10-7 -- Out of Service (lunch etc)
10-8 -- In Service
10-20 -- Location
10-21 -- Call __ by Phone
10-28 -- Vehicle Identification

The Most Common 10 Code Versions
Law Enforcement use one of several 10 code versions. The code version an agency uses depends on the region. The APCO (Association of Police Communications Officers) is the most widely used 10 code version.

Mobile Friendly
Norfolk, VA
Walnut Creek, CA

Code APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-1 Unable to Copy
- Change Location
Signal Weak Police Officer Needs Help Poor Radio Reception
10-2 Signal Good Signal Good Assist Officer Good Radio Reception
10-3 Stop Transmitting Stop Transmitting Clear the Air-Emergency Stop Transmission
10-4 Acknowledgment (OK) Affirmative (OK) O.K., Acknowledgment Message Received
10-5 Relay Relay To / From See a Complainant Relay Message
10-6 Busy - Unless Urgent Busy Investigation Police or Fire Change Radio Channel
10-7 Out of Service Out of Service (a) Out of Service - Off the Air
(b) Out of Service - Subject to Call
Out of Service
10-8 In Service In Service In Service In Service
10-9 Repeat Say Again Arrived at Scene Repeat Message
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-10 Fight In Progress Negative Traffic Detail Off Duty
10-11 Dog Case ___ on Duty (Employee Number) Broken Glass Visitors Can Hear Radio
10-12 Stand By (Stop) Stand By (Stop) Vandalism Advise Weather /
Road Conditions
10-13 Weather-Road Report Weather Conditions (a) Leaking Water Main or Sewer
(b) Hole in the Street / Sidewalk
10-14 Prowler Report Message / Information Convoy or Escort
10-15 Civil Disturbance Message Delivered Have Prisoner in Custody Have Prisoner in Custody
10-16 Domestic Problem Reply to Message Pick Up Prisoner Pick Up
10-17 Meet Complainant Enroute Administrative Assistance Getting Fuel
10-18 Quickly Urgent Detail
10-19 Return to ___ (In) Contact Return to Station Return or Go to ___
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-20 Location Location What is Your Location Location
10-21 Call ___ by Phone Call ___ by Phone Call ___ by Telephone Telephone
10-22 Disregard Disregard Investigate a Break In Cancel or Disregard
10-23 Arrived at Scene Arrived at Scene Breaking In (In Progress) Stand By
10-24 Assignment Completed Assignment Completed Someone in the Building
10-25 Report in Person (Meet) Report to (Meet) Prowler Do You Have Contact
With ___ ?
10-26 Detaining Subject, Expedite Estimated Arrival Time (ETA) Larceny Clear of Warrants
10-27 (Drivers) License Information License / Permit Information Rape Report Subject Wanted
10-28 Vehicle Registration
Vehicle Information Check Full Registration,
License, Motor, Name, Stolen
Registration Check
10-29 Check for Wanted Records Check Person with a Gun Check for Warrants
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-30 Unnecessary Use of Radio Danger / Caution (a) Vehicle Accident
(b) Vehicle Accident Personal Injury
(c) Hit and Run
10-31 Crime in Progress Pick Up Hold Up and Robbery
10-32 Man with Gun ___ Units Needed (Specify) Defective Traffic Light
10-33 Emergency Need Immediate Assistance Execute Warrant Alarm is Sounding
10-34 Riot Current Time Narcotics Investigation
10-35 Major Crime Alert Get a Stolen Auto Report Time Check
10-36 Correct Time Correct Time Correct Time
10-37 (Investigate) Suspicious Vehicle Finished With Last Assignment Please Identify Your Unit
10-38 Stopping Suspicious Vehicle (a) Reckless Driving
(b) Drunk Driver
10-39 Urgent - Use Light, Siren Report of a Dead Person Can ___ Come to Radio?
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-40 Silent Run - No Light, Siren Fight in Progress Suspicious Person-Auto Is ___ Available for Phone Call?
10-41 Beginning Tour of Duty Beginning Tour of Duty (a) Lost Child
(b) Investigate Runaway
10-42 Ending Tour of Duty Ending Tour of Duty Car Improperly Parked
10-43 Information In Pursuit Drunk
10-44 Permission to Leave ___ for ___ Riot Disturbance (type)
10-45 Animal Carcass at ___ Bomb Threat Fight Subject Condition: A to D
10-46 Assist Motorist Bank Alarm Attempted Suicide
10-47 Emergency
Road Repair at ___
Complete Assignment Quickly (a) Injured
(b) Sick
(c) Demented Person
(d) Maternity Case
10-48 Traffic Standard Repair at ___ Detaining Suspect, Expedite Person Overboard
10-49 Traffic Light Out at ___ Drag Racing Barking Dog Proceeding to ___
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-50 Accident:
F - Fire,
PI - Personal Injury,
PD - Property Damage.
Vehicle Accident:
F - Fire,
PI - Personal Injury,
PD - Property Damage.
Court Cases Drugged
10-51 Tow Truck Needed Dispatch Tow Truck General Message Drunk
10-52 Ambulance Needed Dispatch Ambulance Open Door / Window(state Which) Ambulance Needed
10-53 Road Blocked at ___ Road Blocked Gas-Repairs-Wash Person Down
10-54 Livestock on Highway Hit and Run Accident:
F - Fire,
PI - Personal Injury,
PD - Property Damage.
Man Molesting Children Possible Body
10-55 Intoxicated Driver Intoxicated Driver Bomb Threat Coroner's Case
10-56 Intoxicated Pedestrian Intoxicated Pedestrian Unruly Crowd Suicide
(a) - Attempted
10-57 Hit and Run:
F - Fire,
PI - Personal Injury,
PD- Property Damage.
Request BT Operator Tampering With Automobile
10-58 Direct Traffic Direct Traffic Burglar Alarm
10-59 Convoy or Escort Escort Traffic Violator Security Check
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-60 Squad in Vicinity Suspicious Vehicle (a) Dead Dog
(b) Live Dog
(c) Stray Dog
(d) Dog Bite
10-61 Personnel in Area Stopping Suspicious Vehicle Void IBM Card Bike Theft
10-62 Reply to Message B and E in Progress
(Breaking & Entering)
Radio Test
10-63 Prepare to Make Written Copy Prepare to Receive an Assignment Personal Relief Prepare to Copy
10-64 Message for Local Delivery Crime in Progress Eating (state Location)
10-65 Net Message Assignment Armed Robbery Exposure
10-66 Message Cancellation Notify Medical Examiner Send Tow Truck to
(a) Owner Request
(b) Police Request
Suspicious Person
10-67 Clear for Net Message Report of Death Smoke and Flames Visible Person Calling for Help
10-68 Dispatch Information Livestock in Roadway In Commission on Stand-By
10-69 Message Received Advise Telephone Number Held Up By Bridge or Train
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-70 Fire Alarm Improper Parked Vehicle Danger / Caution Prowler
10-71 Advise Nature of Fire Improper Use of Radio False Alarm Shots Fired
10-72 Report Progress on Fire Prisoner in Custody Person Found in Burning Building
10-73 Smoke Report Mental Subject Existing Conditions How Do You Copy?
10-74 Negative Prison / Jail Break Enroute
10-75 In Contact with ___ Wanted or Stolen Dispatch Mechanic
10-76 En Route ___ Prowler Rewind Box (Give Location)
10-77 ETA
(Estimated Time of Arrival)
Direct Traffic at Fire Scene Send VEPCO
(state Gas or Electric),
(b) send C & P (phone)
10-78 Need Assistance Held Up by (state)
10-79 Notify Coroner Courtesy Call
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-80 Chase in Progress Fire Alarm Critical Call (Code Red) Explosion
10-81 Breatherlizer Report Nature of Fire Fire Alarm
10-82 Reserve Lodging Fire in Progress Additional Engine Co.
10-83 Work School Crossing at ___ Smoke Visible Additional Ladder Co.
10-84 If Meeting ___, Advise ETA
(Estimated Time of Arrival)
No Smoke Visible Second Alarm
10-85 Delay due to ___ Respond without
Blue Lights / Siren
Third Alarm
10-86 Officer / Operator on Duty Person Trapped Any Traffic for Me?
10-87 Pickup / Distribute Checks Auto Fire
10-88 Present Telephone # of ___ Request Deputy Chief Provide Cover for Units
10-89 Bomb Threat Request Additional Chief
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-90 Bank Alarm at ___ Transfer Fire Alarm Wire
10-91 Pick Up Prisoner / Subject Check Fire Alarm Box
or Master Box
10-92 Improperly Parked Vehicle Fire Alarm Circuit Open
or Trouble on Circuit
10-93 Blockade Fire Alarm
10-94 Drag Racing Request Gas or Diesel Fuel
10-95 Prisoner / Subject in Custody Grass or Trash Fire
10-96 Mental Subject In Quarters
10-97 Check (Test) Signal Signal Weak Arrived at Scene
10-98 Prison / Jail Break Signal Good Completed Assignment
10-99 Wanted / Stolen Indicated Fireman Need Help
APCO APCO-v0 Norfolk, VA Walnut Creek, CA
10-100 Dead Body Found
10-101 What is Status?
(Are you secure?)
What is Status?
(Are you secure?)
10-106 Secure (Status is secure) Secure (Status is secure)
Download APCO Download APCO-v0 Download Norfolk, VA Download Walnt Creek, CA
Download Above Table (PDF).


Police Radios
Many agencies, especially larger departments, use encrypted digital radios to prevent the public from listening. Some agencies use an analog or digital trunk system, similar to analog and digital cell phone systems. A scanner programmed for that trunk system is required. A basic scanner will receive analog radios, which go back to the last century and still have wide use. Many areas have a mix of systems.

Basic Scanner

Basic police scanners will receive radio transmissions that use Narrow Band Frequency Modulation (NBFM) in 3 different frequency bands (Low, Mid, High). The Low and Mid bands are in part of the Very High Frequency (VHF) band. The scanner High band has a small part of the Ultra High Frequency (UHF) band. Many scanners also pick up Aircraft Amplitude Modulated (AM) radios in the VHF band. Some scanners can receive amplitude modulated (AM) citizens band (CB) radios in the High Frequency (HF) band.

29 - 54 MHz

Low Band ( 29 - 54 MHz )
This band is considered shortwave radio and has longer range than higher frequencies. Police and government public services are allocated the frequencies from 30-50 MHz. Amateur radio (HAM) uses 50-54 MHz (10 meter wavelength), and 29.0-29.7 MHz (6 meter). The HAM 6 meter band can use NBFM, AM (amplitude modulation), or SSB (single side band) modulation. Basic scanners only get the NBFM signals. Citizens Band (CB) radios operate from 26.965 to 27.405 MHz, and use AM. Some scanners can receive CB signals.

FM Radio and Aircraft ( 88 - 137 MHz )
Some scanners get FM broadcast (88 - 108 MHz). Many scanners get Aircraft radios 108-137 MHz (AM).

138 - 174 MHz

Mid Band ( 137 - 174 MHz )
Government fixed and mobile radios are allocated 137-144 MHz. HAM 2 meter radio is allocate 144-148 MHz. Many regional and inter-agency police radios, state and county police, and fire, ambulance (ground and air), hospitals and business's have frequencies in the 148 - 156 MHz band. Marine (ship to ship, ship to shore, waterway traffic, locks, port, and dock operations, and the US Coast Guard) are on frequencies between 156--157.5 MHz. Railroads (operations, Amtrak police, walkie-talkies) have 97 channels (frequencies) between 159.8-157.5 MHz. The National Weather Service (NWS) has 7 channels between 162.4-162.5 MHz that broadcast forecast. The frequencies between 164-174 MHz are licensed for public use.

Marine Channel Frequencies

380 - 512 MHz

High Band ( 380 - 512 MHz )
Aircraft and airport operations use 380-410 MHz. Government mobile radio (Federal and state) use 410-440 MHz. HAM 70 centimeter radio uses 440-450 MHz. The public (includes walkie-talkies) and government (some police departments) have channels between 450-470 MHz. Some older government truck radios use 470-512 MHz. These frequencies are primarily used by broadcast television RF (Radio Frequency) channels 14-20.

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