When you call 911, the call-taker asks for the location of the emergency, including the street address; they also ask for the phone number you are calling from and what is happening. How the call center learns where a caller is has changed since 911 began; Basic 911 means that a call-taker at the local call center answers when someone dials. The emergency and its location are told by voice between caller and call-taker. Enhanced 911 added more. As of November 2026, the call is routed to the right call center for the caller's location; the call-taker's screen shows the caller's phone number and address. For cell phones, Phase I gives the call-taker the phone number and the location of the cell tower. Phase II adds the caller's own location.

The size of the job explains why this matters. NENA estimates that about 240 million calls are made to 911 in the U.S. each year, and in many areas 80% or more are from wireless devices; a phone that is not signed up with a carrier can still call 911. The call center does not get the caller's location, though, and cannot call back if the call is disconnected; that is one reason it helps to know your home address by heart. As of February 2021, the United States had 5,748 primary and secondary 911 call centers, called PSAPs, in 3,135 counties; the system is run by local and state governments, not the national government. Their authority and duties vary from state to state; in most cases, as of November 2026, a 911 call cannot be transferred to another town or state. To reach help somewhere else, call the 10-digit number for law enforcement there.

Text-to-911 is the ability to send a text message to emergency call takers; the FCC says always call if you can, because voice calls give call centers more information. As of November 2026, it is only available in certain places; each call center decides how and whether to accept texts. Where it is not available, the sender should get a bounce-back message. FCC rules say that if a 911 call center asks for text-to-911, wireless carriers and text providers must deliver the service in that area within six months. In 2021 data, more than half of 911 call centers were able to receive texts, with a lot of variation among states; if you call 911 by mistake, do not hang up. A hang-up could make the call-takers think there is an emergency and send help.

Not every problem is a 911 emergency, and, as of November 2026, 911 is for a true emergency, when someone needs help right away; when a problem is not a true emergency, local 911 centers have a separate phone number. A grown-up can search online for it; do not call 911 to ask for it, as of November 2026. When the call is an emergency, say the number as "nine-one-one", so you look for the right buttons on the phone; expect a trained helper to ask what happened, where you are and who needs help. Many centers can tell callers exactly what to do until help arrives, such as step-by-step instructions to help someone who is choking.

Words to know

• cell: mobile phone type
• enhanced: made better
• tower: tall antenna mast
• carrier: phone company
• transferred: moved elsewhere