Number Porting 101: How to Keep Your Business Phone Number When Switching to VoIP
Your phone number is yours. Here’s how to take it with you when you switch providers — and how to avoid the gotchas.
What Is Number Porting?
Number porting is the process of moving your existing phone number from one provider to another. It’s a legal right — the FCC requires carriers to let you take your number with you — and it means you don’t have to change your business number when you switch phone systems.
Your customers keep calling the same number. Your business cards stay accurate. Your website doesn’t need an update. The only thing that changes is the infrastructure behind the number.
It sounds like it should be simple, and conceptually it is. In practice, there are a few things you need to know to keep it smooth.
The Single Most Important Thing You Can Do
Here it is, the one piece of advice that matters more than everything else in this article combined:
Give your new provider a copy of your current phone bill.
That’s it. That’s the thing.
Here’s why: when your new provider submits a port request, your old provider is going to check the details against their records. The name on the account, the authorized contact, the service address, the phone numbers — everything has to match exactly. One wrong character and the port gets rejected.
Your phone bill has all of that information exactly as your current provider has it on file. No guessing, no “I think the account is under…” — it’s right there in black and white. When your new provider has a copy of your bill, they can fill out the port request with information that’s guaranteed to match. And if the old provider rejects it anyway, your new provider has a clear document to point to when escalating.
At Moose Networks, we ask for a recent bill upfront. Not because we’re nosy — because we’ve ported hundreds of thousands of numbers and we know that this one step prevents the vast majority of delays and headaches.
How the Process Works
Step 1: You Decide to Switch
You’ve chosen your new provider. (Good choice, assuming it’s us.) Don’t cancel your old service yet — your existing service needs to stay active during the porting process. This is important. If you cancel first, you can lose your number.
Step 2: Submit a Port Request
Your new provider handles this. You’ll typically need to provide:
- The phone number(s) you want to port
- A copy of your most recent phone bill
- A signed Letter of Authorization (LOA) — a simple form saying “yes, I authorize this transfer”
- Your account number and any PIN or password on the account
We handle the paperwork. You sign one form and hand us a bill. That’s your part.
Step 3: Your New Provider Submits to Your Old Provider
This is where the behind-the-scenes work happens. Your new provider sends the port request to your old provider (the “losing carrier”), who reviews it and either accepts or rejects it.
If accepted, a port date is scheduled. If rejected, there’s a reason code — usually a mismatch in the account details. This is where having that bill copy pays off, because your new provider can identify exactly what didn’t match and resubmit.
Step 4: The Port Completes
On the scheduled date, your number moves to your new provider. Your phones start working on the new system. There shouldn’t be any service interruption — you may see incoming calls arriving on both your old and new systems for about a day as the routing updates propagate across the network, but you won’t miss calls.
Important: contact your old provider after the port completes to confirm they’ve closed your account. The port itself does not always trigger an automatic cancellation on their end. Depending on the web of services and systems your old provider uses, they may not even realize the number has moved — and they may keep billing you until you tell them. A quick call or email after the port goes through saves you from paying for a service you’re no longer using.
How Long Does It Take?
The honest answer: one to two weeks for most ports.
The timeline is mostly determined by how quickly your old provider processes the request. Your new provider can push, but they can’t force speed. What they can do is submit clean, accurate paperwork so nothing bounces back for corrections — which is, again, why that bill copy matters.
The Gotchas (and How to Avoid Them)
Existing Contracts and Early Termination Fees
Check your current agreement before you start. Some providers lock you into a term — one or two years — with early termination penalties if you leave before it’s up. These can range from annoying to genuinely expensive.
This doesn’t prevent you from porting. You can still take your number. But you may owe your old provider a termination fee. Know what you’re walking into so there are no surprises on your final bill.
Port-Out Fees
Some providers charge a fee to release your number. This is legal in many cases, though the amounts vary. It’s usually modest — $5 to $25 per number — but if you’re porting a lot of numbers, it adds up. Check your current provider’s terms or ask them directly.
Large Ports: Start With a Test Number
If you’re porting more than a couple dozen numbers, we recommend porting a single “test number” first before submitting the rest. This lets us confirm that the account details are correct, see how your old provider handles the request, and project the timeline more accurately for the full batch. It takes a little patience upfront but saves a lot of headaches on the back end — especially if your old provider has any quirks in how they process port-outs.
Partial Ports
If you have multiple numbers on an account and you’re only porting some of them, that’s called a partial port. These can be trickier because your old provider needs to keep the account active for the remaining numbers while releasing the ones you’re moving.
Partial ports aren’t a problem, but they require a bit more coordination. Make sure your new provider knows which numbers are moving and which are staying.
The “Don’t Cancel First” Rule
We said it above, but it bears repeating: do not cancel your old service before the port completes. If your account is closed, your number may be released back into the pool and assigned to someone else. At that point, getting it back ranges from difficult to impossible.
Your old service stays active during the port. The port itself is what terminates the old service. Let the process work.
Account PINs and Passwords
Many providers require a PIN or password to authorize changes on your account, including port-outs. If you don’t know yours, call your current provider and get it before you start the process. This is a common reason for port delays — everything else is correct, but the PIN is missing or wrong.
FAQ
Will my phones stop working during the port? No. Your existing service stays active until the port completes. On the day the port goes through, you may see incoming calls landing on both your old and new systems for about a day — but you won’t have any gap in service.
Can I port a number from any provider? Almost any. Landlines, wireless numbers, VoIP numbers — they can all be ported in most cases. The only exceptions are some very old or very rural numbers, and even those can usually be worked out.
What if my old provider tries to block the port? They can’t legally refuse a valid port request. They can reject it for technical reasons (mismatched information), but they can’t refuse to let you leave. If you’re running into resistance, your new provider should be able to escalate.
Can I port numbers from different providers at the same time? Yes. If you have numbers spread across multiple carriers, we can run those port requests in parallel.
How many numbers can I port at once? As many as you need. We’ve handled single-number ports and we’ve handled ports of 250,000 numbers in a single month. The process scales.
Do I need to be there on the day the port completes? Not usually. If your phones are already set up on the new system, everything cuts over automatically. It’s anticlimactic by design.
If you’ve been putting off switching providers because you’re worried about losing your number — don’t. Porting is routine. It’s well-understood. And with a provider who’s done it a few thousand times, it’s about as stressful as changing your mailing address. Maybe less, because we don’t moose around with your phone numbers.
Already know you want to switch? Check out our guide on how to set up a hosted PBX or read about the signs your business has outgrown its phone system. Or just get in touch — we’ll walk you through the whole thing.