What Is a 10-42 Police Code? 10-42 Police Code

The 10-42 police code meaning for the police forces is End Duty.

The 10-42 Police Code is one of the most commonly recognized and respectfully acknowledged codes in law enforcement. If you’ve ever heard an officer mention “10-42” over the radio, you might be wondering — What Is 10-42 Police Code? In police terminology, the 10-42 Police Code simply means “End Duty.” It signifies that a police officer has completed their shift and is signing off for the day. However, this code can also hold a deeper, more symbolic meaning, especially during tributes or memorials for fallen officers.

Understanding the 10-42 Police Code is important for those studying police communication protocols, emergency response systems, or anyone with an interest in public safety communications. Used across various law enforcement agencies in the United States, the 10-42 code is part of the standardized APCO Ten Signals system — a series of shorthand codes first introduced in 1937 to streamline radio communications and reduce errors in high-stress situations.

Why Is the 10-42 Police Code Important?

The use of 10 codes like 10-42 helps police officers and dispatchers exchange vital information efficiently and clearly without using long or potentially confusing sentences. For example, instead of stating “I am ending my shift now,” an officer can simply say “10-42” — a quick and effective way to close communication in a busy dispatch environment.

When asking what is 10-42 Police Code? it’s also essential to note that it sometimes carries ceremonial weight. In many departments, 10-42 is broadcast during funeral processions or remembrance ceremonies, symbolizing that the officer’s “final tour of duty” is complete. This moving tribute reminds us of the service and sacrifice involved in law enforcement careers.

10-42 Police Code Meaning

Code: 10-42
Meaning: End Duty
Context: Used by law enforcement officers to indicate that their duty or shift has ended. Also used as a memorial sign-off for fallen officers.

Whether you’re a law enforcement student, a radio enthusiast, or simply someone trying to understand more about police codes, knowing what is 10-42 police code gives you insight into the efficiency and tradition embedded in public safety communication systems. These codes aren’t just about brevity — they’re also about respect, structure, and honoring those who serve.

If you’re interested in learning more beyond the 10-42 Police Code, our website provides a full guide to all commonly used police 10-codes and their meanings across various states in the U.S.

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What Is 10-42 Police Code? Complete Guide to the 10-42 Police Code in Law Enforcement

Welcome to All Police Codes, your ultimate and trusted source for exploring police signals, ten-codes, and emergency communication terminology used by law enforcement agencies across the United States. Whether you’re curious about what a 10-42 Police Code means or want to understand how it fits into the larger police communication system, you’re in the right place.

We’ve built a detailed, easy-to-use police code lookup website to help anyone—from students to enthusiasts to professionals—quickly find accurate meanings of ten-codes like the 10-42 Police Code, as well as all other active police codes used throughout the U.S.

10-42 Police Code Meaning: End of Tour / Officer Off Duty

So, what is a 10-42 Police Code? The 10-42 code is one of the most recognized signals in the law enforcement world. It signifies “End of Tour” or “Officer Ending Duty”. Officers use this code when they finish their shift, letting dispatch and their fellow units know that they are officially signing off duty. In many cases, especially during ceremonies or final calls, 10-42 is also used as a respectful, symbolic message indicating a fallen officer’s final sign-off.

Why Police Use Ten Codes Like 10-42

The 10-42 police code, along with dozens of other ten-codes, helps police officers communicate clearly and efficiently. These codes eliminate the need for long, detailed explanations and reduce the chances of miscommunication during high-pressure situations. Instead of saying, “I’m done with my shift and leaving the station,” an officer simply says “10-42,” making the message quick and standardized.

This system plays a crucial role in streamlining dispatch calls, ensuring faster response times, and maintaining organized records of officer availability.

A Brief History of Police Codes: The Origin of 10-Codes

Police ten-codes were first developed between 1937 and 1940 by the Association of Public-Safety Communications Officials-International (APCO). The goal was to create a concise and effective shorthand for police radio communication. In 1974, APCO expanded and formalized the list of codes for broader national use.

Interestingly, the roots of the code system go even further back. In 1935, APCO proposed a Morse code-based brevity system influenced by U.S. Navy communication symbols, although those were designed for Morse—not voice—transmissions. Over time, these evolved into the verbal radio codes used in police departments today.

Real-World Use of 10-42 in Law Enforcement

The 10-42 police code often appears during routine sign-offs, but it’s also used in ceremonial contexts. For instance, when an officer retires, their final call may include a 10-7 code (indicating “Out of Service”) followed by 10-42 as a respectful note of their service ending. In cases of line-of-duty deaths, a symbolic 10-42 call may be broadcast over radio as a tribute.

If you’re using a police scanner, you might hear “10-42” being announced toward the end of a shift or during dispatch summaries. It’s a common and meaningful code among patrol units, dispatchers, and law enforcement supporters.

Learn More Police Codes Like 10-42

The 10-42 Police Code is just one of many important police codes in regular use today. From 10-4 (Acknowledged) to 10-99 (Wanted/Stolen), each code plays a role in building fast, effective, and discreet communication channels between emergency personnel.

At All Police Codes, we provide free, up-to-date resources to help you explore the full catalog of police radio codes in use across the United States. We love sharing this information with the public and honoring the hard work of our emergency responders.

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