Enhanced 911 (E911) is the 911 capability that automatically sends a caller’s callback number and location to the public safety answering point (PSAP), the call center that answers emergency calls for an area. Basic 911 only connects the call; E911 tells the dispatcher who is calling and where they are, which matters when a caller can’t speak, doesn’t know the address or gets cut off. For businesses, E911 is mostly about making sure the phone system sends the right location for every phone, softphone and remote user.
At a glance
- E911 delivers the caller’s callback number and location to the 911 call center along with the call.
- Mobile carriers supply location from the network and the device; business and internet phone systems rely on addresses and location data that you or your provider maintain.
- In the US, FCC rules set E911 requirements for wireless carriers and interconnected VoIP providers, and separate rules cover multi-line business phone systems; some states add their own.
- Wrong or missing location records are the most common failure, especially after office moves and with remote workers.
- E911 is being upgraded over time to IP-based Next Generation 911, which can carry richer location data and other media.
What problem it solves
When someone dials 911, the dispatcher needs to know where to send help. With a single landline at a fixed address, that was straightforward. Business phone systems, mobile phones and internet calling broke the link between a phone number and a place: a call from a large campus might show only the headquarters address, and a softphone call from an employee’s kitchen might show an office in another state. Misrouted or unlocatable calls delay help, and the consequences can be tragic, as our podcast episode A Child Died Dialing 911 describes.
E911 addresses this by attaching location to the call automatically, so the call reaches the right PSAP and the dispatcher sees an address, and for business systems ideally a floor or room, without having to ask.
How it works
Routing. When a 911 call is placed, the network uses the caller’s location to route it to the PSAP that serves that area.
Callback number. The call carries the caller’s number, based on automatic number identification (ANI), so the dispatcher can call back if the call drops.
Location. The dispatcher’s system looks up or receives the caller’s location. How that location is produced depends on the type of phone:
- Landlines use the service address on record for the line.
- Mobile phones use network and device-based methods. US rules evolved in phases, from the location of the cell site to more precise coordinates, and later added indoor and vertical accuracy requirements for wireless carriers.
- VoIP and cloud phone systems rely on a registered address for each user, device or site, or on a location the system determines from network information such as the subnet, Wi-Fi access point or switch port. Many unified communications and hosted PBX platforms can update location automatically when a user moves, or prompt softphone users to confirm where they are.
Business phone systems. In the US, multi-line telephone systems (MLTS) are also subject to Kari’s Law, which covers direct 911 dialing and on-site notification, and to the dispatchable location rules adopted under the RAY BAUM’S Act, which call for a usable address plus details such as floor or suite. Which rules apply, and who is responsible for each part, depends on the system and how it is provided.
When it matters for buyers
- When moving to a cloud phone system or Microsoft Teams calling. Emergency locations, routing and notifications have to be set up in the new platform before go-live.
- When opening, moving or closing offices. Every location change needs its emergency addresses updated.
- When staff work remotely. Softphones and home phones need a current location, and users need to know how to update it.
- When replacing copper lines. Lines that served elevators, alarm panels and lobby phones often carry 911 calls; replacements must still support them.
- During compliance reviews. You may need to show how direct dialing, notification and location work, site by site, across the states where you operate.
Questions to ask vendors
- How does your platform determine location for desk phones, softphones and mobile apps, and what happens when a user moves?
- What location detail do you send: street address only, or floor, suite or room?
- Who maintains the location records, and how are we alerted when one is missing or wrong?
- How do you support on-site notification of 911 calls, and to whom can it be sent?
- What happens to 911 calls during an internet or power outage at our site?
- How do your features map to the federal and state rules that apply where we have phones?
- What 911 fees and surcharges will appear on our bill, and how are they calculated?
How it differs from Next Generation 911 (NG911)
E911 adds callback number and location to 911 calls, largely on top of older telephone network technology. Next Generation 911 (NG911) is the ongoing move of the 911 system itself to IP-based networks, which can carry richer location data, text and, over time, other media to PSAPs. NG911 is an upgrade to the emergency network run by public authorities, not something a business buys; its rollout varies by state and region. For businesses, the practical job is the same either way: make sure your phone system sends an accurate location. See our Microsoft Teams PSTN connectivity and hosted PBX pages for how providers handle emergency calling.
Problems this helps with
- Not sure our phone system sends the right address when someone calls 911
- Remote and hybrid staff calling 911 from home on company softphones
- Moving to a cloud phone system and need to set up emergency calling
- Need to know what our 911 obligations are across several states
