Before You Switch to VoIP, Check These 6 Things (Not Just the Price)

Most VoIP decisions start with a quote. Somebody compares the per-user price against the old phone bill, sees the savings, and signs.

Then go-live day arrives. Calls sound choppy at 10 AM. Two desk phones won't power on. The main number is still ringing at the old carrier. And the fax machine in the back office just sits there, blinking.

None of that has anything to do with the price. It has to do with the stuff nobody asked about before the contract was signed.

Our engineers have walked a lot of offices through this switch, and the same six things come up again and again. Check them before you move, and the move is boring. That's the goal.

1. Your internet (and what else is using it)

VoIP turns every call into data on your internet connection. So the first question isn't "how fast is our internet?" It's "how steady is it when everyone is using it?"

A single voice call doesn't need much bandwidth. What hurts calls is jitter, latency and packet loss, usually caused by something else hogging the line: cloud backups, video meetings, a big file upload, guest Wi-Fi.

Before you switch:

Run a speed and quality test during your busiest hour, not at 7 AM when the office is empty.
Check your router or firewall for QoS (quality of service), so voice traffic gets priority.
Turn off SIP ALG if your router has it. It's a common cause of one-way audio and dropped calls.
Think about a backup connection if phones are how you make money. A second line or a cellular failover can keep calls moving when the main circuit goes down.

2. Cabling, switches and PoE

Here's the one that surprises people on install day. Most IP desk phones get their power through the network cable, using Power over Ethernet (PoE). If your network switch doesn't supply PoE, those phones stay dark unless you add power adapters or injectors.

Walk the office and check:

Does every desk that needs a phone have a working network jack?
Do your switches support PoE, and do they have enough total power for every phone you plan to plug in?
Is the cabling old or patched together? Bad cable shows up as random call drops that are hard to trace.

Some teams skip desk phones entirely and use a softphone app on their computer or cell. That works great for a lot of roles. But decide that on purpose, not because you found out the switches can't power anything.

3. Number porting

Your phone number is part of your business. It's on your website, your Google listing, your trucks and your old invoices. Moving it to a new provider is called porting, and it's the step most likely to cause delays.

Porting goes smoothly when the paperwork matches exactly. Before you start, get from your current carrier:

The account number and any account PIN or passcode
The authorized name and service address, exactly as the carrier has them on file
A full list of every number on the account, including fax lines, direct lines and that old toll-free number nobody remembers

One more tip: don't cancel your old service before the port completes. Canceling first can release the number, and getting it back is a headache you don't want.

The price gets you to sign. The six boring checks decide whether anyone notices you switched.

4. E911 and emergency calling

With a traditional landline, 911 knew where the phone was because the line was tied to a building. With VoIP, a phone can be plugged in anywhere, so the emergency address has to be set up on purpose.

In the US, FCC rules (Kari's Law and RAY BAUM'S Act) require that business phone systems let people dial 911 directly, without a prefix like "9," and send a dispatchable location, like a building, floor or suite, with the call.

What to confirm with any provider:

Every phone or location has a registered emergency address, and it's specific enough for responders to find the right room.
Remote and hybrid staff are covered. Someone working from home with a softphone needs their location handled too.
Someone on-site gets notified when a 911 call is placed, so the front desk can meet responders at the door.

This isn't the fun part of a phone project. It's the most important one.

5. Fax and other analog stuff

Plenty of businesses still fax. Clinics, insurance offices, law firms and real estate teams use it every day. Old fax machines were built for analog phone lines, and they often don't play nicely when you plug them into a VoIP adapter.

It's not just fax. Look around for other devices that quietly use a phone line:

Alarm and security panels
Elevator emergency phones
Older credit card terminals
Door and gate entry systems

For fax, the cleanest fix is usually moving to eFax, where faxes arrive as PDFs in email or a shared inbox and you send them the same way. For the other devices, make a list before you switch, so you can decide what needs its own line and what can move.

6. Training (the part everyone skips)

A new phone system changes small habits. How to transfer a call. How to park a call and pick it up at another desk. Where voicemail lives now. How to log in to a call queue.

Skip training, and people fall back on what they know: they stop transferring and just take messages. Within a month, the new system "doesn't work," even though it's working fine.

Plan for:

A short, hands-on session for each team, focused on the five things they'll do every day
A one-page cheat sheet next to every phone or pinned in your team chat
A go-live day with real people on standby to answer "how do I…?" in the moment
A quick check-in a week later, when the real questions show up

The short version

Price matters. But price is the easy part to compare, and the six things above are where switches go sideways:

Internet that holds up when everyone's busy
Cabling and PoE that actually power your phones
Porting paperwork that matches exactly
E911 set up for every location and remote worker
A plan for fax and other analog devices
Training that sticks past the first week

If a provider can't talk you through all six before you sign, that tells you something.

This is the reason we do onboarding the way we do. At ClearConverse, our engineers handle setup with you, from network checks and porting to E911 and eFax, instead of handing you a login and a help article. We put phones, texting, fax and AI receptionists on one platform, set up by real engineers. You can see how it works at clearconverse.com.

Which one of these six caught your team off guard when you switched? Tell us in the responses. We read every one.