Police code 10-8 means “in service” — the officer is on duty, available, and ready to be dispatched. When it comes across a scanner or appears in a report, it tells dispatch that the officer is back in the pool of units that can be sent to the next 911 call, traffic incident, or request for service.
What 10-8 Tells Dispatch
An officer who broadcasts 10-8 is saying one thing: route calls my way. The transmission updates the officer’s status in the department’s Computer-Aided Dispatch (CAD) system, moving them from unavailable to active on the dispatcher’s screen. From that point, the CAD system treats the unit as a candidate when a call drops.
Dispatchers rely on accurate status reporting to know which officers are actually free. If a burglary call comes in, the system identifies the closest available unit, and “available” means 10-8. An officer who forgets to update their status, or reports 10-8 while still tied up on something else, creates a gap that can slow response times. Most departments treat inaccurate status reporting as a policy violation that can lead to internal discipline.
How Officers Use 10-8 During a Shift
The code gets used repeatedly in a single tour. An officer typically transmits 10-8 at the start of the shift after logging into the patrol vehicle’s equipment and confirming everything works. The CAD system flips the unit from inactive to active, and patrol begins.
After finishing any assignment, whether that’s a traffic stop, a welfare check, or a report at a residence, the officer calls 10-8 again. The software marks the previous call as completed and timestamps the transition. Over time, that data builds a detailed record of how long calls take and how many units are available at any given hour, which departments use when making staffing and budget decisions.
Digital Status Updates
Voice radio is no longer the only way to go 10-8. Most modern patrol vehicles have a Mobile Data Terminal, a ruggedized laptop mounted to the dashboard, that lets officers update their status with a button press instead of keying the radio. For routine changes like returning to service after a break or fueling up, many departments expect officers to use the terminal rather than tie up the channel. The CAD system processes these digital updates the same way it handles voice transmissions.
Officers still use voice radio for status changes during higher-risk situations. During a traffic stop or when backing another officer, taking hands off the wheel to tap a screen is a safety problem. In those cases, the officer asks the dispatcher to update their status in the system instead. Emergency responses also stay on voice radio so everyone monitoring the channel has situational awareness.
Codes You’ll Hear Alongside 10-8
A few other ten-codes come up constantly in the same radio traffic, and knowing them helps the picture make sense.
- 10-7 (Out of Service): The opposite of 10-8. The officer is unavailable — meal break, end of shift, vehicle maintenance, or any other reason they can’t take calls. Dispatchers filter 10-7 units off the active roster.
- 10-4 (Acknowledged): The universal confirmation. When an officer calls 10-8, the dispatcher responds 10-4 to confirm the status change was received and logged.
- 10-6 (Busy): The officer is occupied with paperwork, an interview, or a situation and can’t take a new assignment yet. Unlike 10-7, they’re still working; they’re just not free.
Some departments also distinguish between 10-8 (available for new calls) and 10-98 (completed the last assignment). The practical difference is subtle: 10-98 tells dispatch the previous call is wrapped up, while 10-8 confirms the officer is ready for whatever comes next. Not every agency uses 10-98.
Why the Meaning Isn’t Universal
There is no federal law requiring departments to use ten-codes or assigning universal meanings to them. The codes trace to 1937, when the Association of Public-Safety Communications Officials developed the first set of “10 Signals” to reduce voice traffic on limited radio channels. Credit for the concept generally goes to Charles Hopper, then communications director for the Illinois State Police.1Police1. Police 10 Codes vs. Plain Language: The History and Ongoing Debate
APCO tried to standardize meanings nationally through Project 14 in 1974, recommending all departments adopt the same set.2APCO International. Projects That effort never fully took hold. A code that signals a fight in progress in one jurisdiction might mean “off duty” the next county over. 10-8 for “in service” is one of the more consistent assignments across departments, but you can’t assume any specific code carries the same meaning everywhere. The only way to be sure what a code meant on a given recording is to check the department’s own signal list.
After Hurricane Katrina exposed how badly incompatible codes could hamper multi-agency response, the federal government in 2006 formally recommended plain language, and the Department of Homeland Security’s National Incident Management System now requires plain language for multi-agency or multi-jurisdiction events.3Office of Justice Programs. 10-4 No More? Law Enforcement Agencies Are Phasing Out Old Radio Codes For internal, single-department operations, ten-codes remain common, which is why you still hear 10-8 on scanners today.
How 10-8 Records Show Up in Court
Every time an officer transmits 10-8 or updates status through a terminal, the CAD system creates a timestamped record. Those records regularly surface in legal proceedings. Defense attorneys use them to challenge an officer’s account of when they arrived at a scene or how long a stop lasted. Prosecutors use them to establish timelines. Internal affairs investigators use them to confirm whether officers were where they said they were.
CAD logs and radio recordings generally come in under two Federal Rules of Evidence exceptions to the hearsay rule. The business records exception covers records made at or near the time of an event, kept as part of a regularly conducted activity, when making such records was standard practice. The present sense impression exception covers statements made while or immediately after perceiving an event, which fits a real-time radio transmission.4Legal Information Institute (LII) / Cornell Law School. Federal Rules of Evidence Rule 803 – Exceptions to the Rule Against Hearsay
Retention periods vary by department and state records-retention schedules. No single federal rule governs how long police agencies must keep radio logs. If you need a copy of a specific transmission for a legal matter, file the records request sooner rather than later. Waiting a year or more risks finding that the recording has been purged under the department’s retention policy.