Before You Call 911 on a Cell Phone

There's a difference between calling 911 on a mobile phone and calling from a landline. The difference has to do with how the calls are routed and how they're tracked. If you know what to expect, you're more likely to get the help you need when you need it.

In most parts of the United States, when you call 911 from a landline, emergency responders can find you—even if you don't know where you are or you can't speak.

When you call 911 from a traditional landline (a telephone connected to the lines on the poles) a computer in the dispatch center will show the number and address of the phone you're using.

The ANI/ALI (automatic number identification/automatic location identification) is standard equipment in any Public Service Answering Point (PSAP), colloquially known as the 911 center.

When you make a 911 call on a cell phone, you are sending signals through the air. The tower that picks up your phone's signal may be near or not. That's not enough information for the dispatcher to find you. It's like playing "Marco Polo" in the pool when you're blindfolded and only have sound to guide you.

When you call 911 from a mobile phone, the call often lands in a regional center. A call-taker in a far-away city or county may answer. In this case, you'll need to supply some important information.

Before they can dispatch help, there are two pieces of information the call-taker needs to know immediately:

1. The city you're calling from
2. The type of emergency you have (police, fire, or ambulance)

Different emergency services use different dispatch centers. Once they have the information they need the call-taker can transfer you to the correct center.

Wireless carriers are required to complete 911 calls, even when the phone is not activated. Any phone that turns on and can receive a signal is capable of making a 911 call.

Professional call-takers are trained to get information from you. They're staring at a computer screen that has all the relevant questions. Listen carefully and answer as concisely as possible.

The National Emergency Number Association (NENA) reports that in 2011, more than 31% of U.S. households were only using a wireless phone. Additionally, NENA reports that in 2011, there were 146 million 911 calls from mobile phones.