Introduction to 911

The number 911 is the three digit number that has been designated for public use to report an emergency and/or request emergency assistance throughout the United States. The number 911 is intended as a nationwide universal telephone number that provides direct access to a Public Safety Answering Point (PSAP). 

Public Safety Answering Point

A PSAP is an agency or facility which is designated and authorized to receive and respond to emergency calls requiring one or more public services such as police, fire, or ambulance service.

Any one agency or group of agencies may be designated as a Public Safety Answering Point.

Close Coordination

Close coordination among agencies providing emergency services is a valuable capability provided by E-9-1-1. Advantages to the public include one universal three-digit number that is easy to remember and that can be called for any emergency services provided within a given 9-1-1 service area. 

Confusion is avoided, and time can be saved since a caller does not have to remember or look up seven-digit directory number to report an emergency situation or request emergency services.

Designated by the Municipality

A 911 service area is established on a municipal basis. Public Safety Answering Points within the 911 service area are designated by the municipality. A municipality may be a city, town, community, county, or a combination of these or other political entities. 

The scope of services to be provided and the agencies associated with a PSAP are determined by the municipality.


One or more operators are located at a PSAP facility to receive and handle emergency calls in accordance with a municipality's requirements. PSAP operators may be personnel from one or more agencies, such as the police or fire department, or any agency designated to receive 911 emergency calls. Depending on the municipal requirements and procedures, a PSAP operator may need to serve 911 emergency calls by:

  • Serving as a dispatcher for one or more agencies
  • Collecting and relaying emergency information to the proper agency
  • Transferring the call to the proper

One or more PSAPs may be required for any given municipality or metropolitan area.