VoIP 911: What Actually Happens When You Dial
E911 on VoIP doesn’t work the way you think it does. Here’s what actually happens, what can go wrong, and why your provider probably hasn’t explained it well.
Nobody Wants to Write This Article
We get it. Emergency services aren’t fun to think about. They’re not good marketing. Nobody’s going to share “what happens when you dial 911 on your office phone” on LinkedIn.
But here’s why it matters: if you’ve moved from traditional phone lines to VoIP — or you’re about to — the way 911 works has fundamentally changed. And most VoIP providers do a terrible job explaining that, because the explanation includes phrases like “it might not work the way you expect,” and that’s not great for sales.
We’d rather you know how it actually works than find out during an emergency.
How 911 Works on a Landline
On a traditional copper phone line, 911 is almost magical in its simplicity. You dial. The call goes to the local Public Safety Answering Point (PSAP) — that’s the 911 dispatch center. Your location pops up on the dispatcher’s screen automatically, pulled from the phone company’s database. The dispatcher knows where you are before you say a word.
This works because copper lines are physically wired to a specific address. The phone company knows which wire goes to which building. The ALI (Automatic Location Identification) database maps the phone number to the address. It’s been this way for decades, and it’s extremely reliable.
The key thing to understand: on a landline, your location is a property of the physical wire. It doesn’t depend on anyone entering an address correctly, or a database being updated, or software working. The wire goes to your building. That’s your location. Done.
How 911 Works on VoIP (E911)
VoIP phones aren’t connected to a physical wire that maps to an address. They’re connected to the internet. Your phone could be in your office, in your home, in a hotel room, or in a different state. The network has no inherent way to know where you are.
So VoIP uses a system called E911 (Enhanced 911). Here’s how it actually works:
1. You register an address. When your VoIP service is set up, someone — you, your provider, your IT person — enters a physical address for each phone number or extension. This address goes into a database.
2. You dial 911. The call is routed through your VoIP provider’s network to a 911 routing service. The major ones are Bandwidth, Intrado, and West Safety Services.
3. The routing service looks up your address. It queries the database where your registered address is stored, determines which PSAP serves that address, and routes the call there.
4. The PSAP receives the call with your registered address. The dispatcher sees the address you (or your provider) entered during setup. They dispatch responders to that address.
Notice the difference? On a landline, the location comes from the physical infrastructure. On VoIP, the location comes from a database entry that someone typed in. If that entry is wrong, the dispatcher gets the wrong address.
What Can Go Wrong
This is the part your provider probably didn’t walk you through during onboarding.
The Address Is Wrong
This is the most common failure, and it’s almost always a human error. Someone typed the wrong suite number. The street address was entered as “123 Main” when the PSAP’s database expects “123 N Main St.” The initial setup used the company’s headquarters address, but the phone is actually at a branch office.
In the best case, the dispatcher asks “can you confirm your location?” and you correct it verbally. In the worst case — if you can’t speak, if there’s smoke, if you’re having a medical emergency — responders go to the wrong place.
The Phone Moved But the Address Didn’t
This is the one that catches people. Your VoIP phone works anywhere there’s internet. You unplug it from your office, take it home, plug it in, and it works perfectly — calls, voicemail, everything. But the E911 address is still your office.
If you dial 911 from home, responders go to your office. No one is at your office. You’re at home, having an emergency, and help went to the wrong building.
This is especially relevant now that remote and hybrid work is normal. If your team has VoIP phones at home, every single one needs a correct E911 address for the home location. And if someone moves, that address needs to be updated. This isn’t optional — it’s an FCC requirement, and more importantly, it’s the difference between help arriving and help not arriving.
Power and Internet Outages
Your copper landline worked during power outages because the phone company provided power over the copper wire. VoIP phones need electricity and internet. No power or no internet means no phone, which means no 911.
Some things that help: battery backup (UPS) on your network equipment, a cellular failover connection, or — and this is the simplest one — making sure everyone knows to use their cell phone for 911 if the office phones are down. That last one sounds obvious, but in a stressful situation, people reach for the phone on their desk out of habit.
The Provider’s 911 Routing Fails
Your VoIP provider relies on a third-party 911 routing service to deliver the call to the right PSAP. If that service has an outage, your 911 call may not route correctly — or at all. This has happened. It’s rare, but it’s happened.
In July 2022, a major 911 routing outage affected multiple VoIP providers simultaneously because they shared the same underlying 911 delivery platform. The providers’ regular phone service worked fine — it was specifically the 911 routing path that failed.
Nomadic Users and Softphones
Softphones — apps on your laptop or cell phone that act as your office extension — make the address problem even harder. Your laptop could be anywhere. If you’re using a softphone from a coffee shop and dial 911, the registered address might be your office, your home, or wherever someone entered during setup.
The FCC requires providers to give users a way to update their E911 address. Some providers make this easy (a button in the app). Some bury it in the account portal. Some require you to call support. If you use a softphone, find out how to update your address now, not during an emergency.
What the FCC Requires
The FCC has specific rules for VoIP 911 (called “interconnected VoIP” in regulatory language):
- Providers must transmit 911 calls along with the caller’s registered location and callback number to the appropriate PSAP.
- Providers must give users a way to update their registered location. The FCC has explicitly said that providers cannot charge extra for E911 — it’s a required capability, not a premium feature.
- Providers must warn customers about the limitations of VoIP 911 compared to traditional 911. This usually takes the form of a disclosure during signup that most people click through without reading.
The rules are real, but enforcement is complaint-driven. And the dirty secret is that many providers treat E911 compliance as a checkbox — they technically meet the requirements without making sure their customers actually understand how it works or have correct addresses on file.
What You Should Do
1. Verify Every E911 Address Right Now
Log into your provider’s portal and check the E911 address registered for every phone number and extension on your account. Verify that each one matches the physical location where that phone actually sits. If you can’t find the E911 settings in your portal, call your provider and ask.
This is the single most impactful thing you can do. It takes 20 minutes and it could save a life.
2. Handle Remote Workers
If any of your employees use VoIP phones or softphones from home, each one needs their home address registered as their E911 location. If someone splits time between the office and home, they need a way to update their address — or you need to have both locations registered (some providers support this, some don’t).
Ask your provider how they handle multi-location E911. If the answer is “the user has to log into the portal and change it manually each time,” that’s technically compliant but practically useless. Look for providers that offer automatic location detection or at least make the update process simple enough that people will actually do it.
3. Have a Backup Plan for Outages
During a power or internet outage, your VoIP phones won’t work. Make sure your team knows: use your cell phone for 911 if the office phones are down. Cell phones transmit GPS location to 911, which is actually more accurate than VoIP E911 in most cases.
If you have critical facilities — a warehouse, a manufacturing floor, somewhere people might be in danger — consider whether battery backup on the phone system is worth the investment.
4. Label Your Phones
If you have phones in common areas — a lobby, a break room, a conference room — put a small label on or near the phone with the building address. In a stressful situation, people sometimes can’t remember the address they’re at. A label costs nothing and could matter a lot.
5. Test It (Carefully)
Some PSAPs allow non-emergency test calls. You can also call your provider and ask them to verify the 911 routing for your numbers. This is a moose-t for any business that takes safety seriously — don’t assume it works just because someone set it up years ago.
A Note About Multi-Location Businesses
If you have multiple offices, each location needs its own E911 configuration. This sounds obvious, but we’ve seen setups where every phone across five offices has the headquarters address registered for 911. That means if someone at the branch office dials 911, responders go to headquarters — possibly in a different city.
If you have a multi-location setup, verify E911 at every site. Each phone needs the address of the building it’s physically in, not the address of the main office.
What We Do About This
When we set up a customer, we register E911 addresses as part of the provisioning process — it’s not an afterthought or an optional step. We verify addresses against the MSAG (Master Street Address Guide), which is the database that 911 routing actually uses, to make sure the address format matches what the PSAP expects.
For customers with remote workers, we make it straightforward to set and update E911 addresses for home locations. We’d rather spend the time getting this right during setup than deal with the consequences of getting it wrong.
We’re not going to claim our 911 implementation is fundamentally different from other providers’ — the underlying technology is the same industry-wide. But we take the setup seriously, we make sure customers understand how it works, and we don’t bury the limitations in fine print.
Not sure if your E911 is set up correctly? Drop us a line — we’re happy to walk through what to check, whether you’re our customer or not. This is the kind of thing where getting it right matters more than who you buy phone service from.