What is the meaning of 10-4?

By Cheezem 3 Min Read

Sometimes, simplicity in communication is best and you must’ve noticed simple code words being used to communicate multiple times. Whether it be in the police force, military, or while driving, code words get used most often for faster communication. Even you as a kid might’ve formed some kind of code words to communicate with your friends for some fun. One such that is commonly used in various spheres of life is “10-4.” It is s common one and you must’ve heard it in movies mostly, but it is widely used in the real world as well.

In this article, we’ll delve into the origins and significance of this seemingly straightforward phrase, and understand this simple way of communication. So, buckle up as we navigate the linguistic highways of “10-4” to decode its true essence.

What does code 10-4 mean?

The code 10-4 is commonly used by police, military, and truck drivers. It is an easy way of communication and what it means is nothing complicated. The code 10-4 means that the information received has been “understood” or “OK”. Therefore, 10-4 simply means I have understood and that the speaker understands that you understand the information that has been given to the listener.

What is 10-4 police code?

In the realm of law enforcement or police, the 10-4 code means understood. Therefore, it is confirmation that the received information has been accepted and acknowledged. So, while going around the town, you might hear a police officer speaking into the microphone 10-4. Although, most of the time you will hear it being spoken in movies.

Police officers trying to communicate

How did 10-4 get its name?

The code 10-4 gets its origins from the collection of “ten codes” which was established by the director of Illinois State Police, Charles Hopper around the 1930s. The codes were a particularly effective method for police officers to send signals to one another and back to headquarters because two-way car radios had just been developed. To assist in standardizing usage across state lines, the Associated Police Communications Officers, or APCO, released a list of roughly 100 ten codes in 1940.

However, the 10 that comes before all the codes is to make sure that the connection is working and that the message is being conveyed.


In the world of communication, where brevity and clarity are paramount, “10-4” stands as a shining example of how a simple code can transcend its origins and become a universal symbol of understanding. From its humble beginnings in the realm of radio communication to its widespread use in everyday language, “10-4” has come to symbolize agreement, acknowledgment, and cooperation.

Share This Article
Leave a comment