How to Port a Business Phone Number Without Losing Calls
To port a business phone number, open service with the new provider, give it your account details exactly as the current carrier has them on file (account name, service address, account number, billing telephone number and any PIN), sign the letter of authorization, and leave the old service running until the number moves on the date the old carrier confirms. FCC rules give a simple landline or landline-to-wireless port one business day and a non-simple port four business days. Budget a week of overlap so no customer hits dead air.
How a port moves your number
The new provider (the gaining carrier) files the request. Your current carrier (the losing carrier) checks it against its records and either rejects it or confirms a date, usually called the FOC, short for firm order commitment. On that date the number’s routing changes and the old carrier disconnects the line.
The clock is set by 47 CFR 52.35. A simple wireline-to-wireline or intermodal port has to be completed within one business day, and a request that reaches the old carrier between 8 a.m. and 1 p.m. local time is eligible to go live at midnight the same day. Ports that are not simple get four business days. Either deadline stretches if you ask for a later date. An account with several lines, a hunt group or a phone system is often handled as non-simple, so ask the new provider which kind yours is.
Notice what you do not do: cancel the old account. Verizon’s port-out page warns customers not to disconnect until the number has moved, because a disconnected number has to be reactivated before anyone can port it.
Port phone number paperwork: CSR, LOA and BTN
The paperwork is where business ports stall. Gather these before you submit anything.
| Item | What it is | Where you get it | The trap |
|---|---|---|---|
| CSR (customer service record) | The old carrier’s record of your account: legal name, service address, every number and feature | Ask the current carrier’s business support for a copy | The name on it may be the owner’s personal name or an old trade name, not the company name you use now |
| LOA (letter of authorization) | Your signed permission for the new provider to move the numbers | The new provider prepares it, often as an e-signature | It must be signed by the person authorized on the account. Twilio, for example, cancels a request if the LOA is not signed within 30 days |
| BTN (billing telephone number) | The main number the whole account is billed under | Top of the bill or the CSR | Porting the BTN while other lines stay behind forces the old carrier to re-bill the rest under a new main number. Tell them first |
| Account number and PIN | Identifies the account; the PIN or passcode only if one was set | Bill, online account; mobile carriers issue a port-out PIN | Mobile PINs expire. Verizon’s Number Transfer PIN lasts 7 days |
For a simple port, 47 CFR 52.36 limits the old carrier to a short list of standard fields. On your side that comes down to the number, the account number, the ZIP code and a passcode if you created one. Copy each exactly as the bill or CSR shows it, suite numbers included.
A cutover plan with no dead air
- List every number on the account. Main line, rollover lines, fax, alarm line, any toll-free number pointing at the main line. Mark each one move, keep or cancel.
- Build the new service on a temporary number first. Set up ring order, hours, the voicemail greeting and after-hours forwarding while nothing is at stake, so the real number lands on a finished setup.
- Request the CSR, then submit the port. Enter the details exactly as the CSR shows them and sign the LOA the same day.
- Pick the date on purpose. A Tuesday or Wednesday beats a Monday, a Friday or the day a cold snap is forecast.
- Keep both phones within reach on port day. Not every carrier can promise an exact time on the port date, so calls can keep ringing the old service for part of the day.
- Test from outside. Call from a cell on a different carrier. Check that it rings the new service, that outbound caller ID is right, that voicemail answers and that a test text arrives.
- Then close out the old side. Confirm the ported lines are off the old account, cancel anything left over and keep the final bill.
For a three-truck plumbing shop moving a copper main line and a fax to a VoIP provider, with two rollover lines left behind:
| Day | What happens |
|---|---|
| Monday | Owner asks the old carrier for the CSR and learns the account is still in his own name, not the LLC |
| Tuesday | New service built on a temporary number; port submitted in the name the CSR shows; LOA signed |
| Thursday | Old carrier confirms the port for the following Wednesday |
| Port Wednesday | Test calls at 7 a.m. land on the new service; the fax line follows by mid-morning |
| Following week | Rollover lines canceled, final bill checked |
Nine days end to end, and not one missed call, because nothing was canceled until the number answered somewhere new.
Why ports get rejected, and the fix
Twilio publishes the rejection reasons losing carriers send back. The categories make a good checklist for any port.
| Rejection | What it means | Fix |
|---|---|---|
| Invalid end user name | The company name does not match the old carrier’s record | Use the name exactly as it appears on the CSR, even if it is out of date |
| Invalid address | The address does not match the record for that number | Use the service address, not the mailing address |
| Invalid PIN | The PIN does not match | Generate a fresh one; mobile PINs expire |
| Invalid account number | The account number does not match | Copy it from the current bill |
| Number inactive or disconnected | The line was canceled too early | Reactivate it with the old carrier, then resubmit |
| Carrier restriction | Something on the old account blocks the move, such as a port lock | Remove the lock (Verizon calls it Number Lock) and resubmit |
Each rejection restarts part of the process. Moving a cell line off Verizon has its own steps, covered in the guide to porting a number out of Verizon, and moving a shop landline onto a mobile plan is covered in porting a landline number to a cell phone.
What breaks after the number moves
The number arrives. Several things tied to it do not.
- Business texting. If you text customers from the number through an app, the new provider has to attach it to a registered A2P 10DLC campaign on its side. Twilio notes that unregistered traffic draws extra carrier fees.
- Voicemail. Old messages and greetings stay on the old carrier’s system and disappear with the line. Save what you need.
- Forwarding rules. Star-code forwarding set on the old carrier stops when the number leaves. If an answering service or an AI receptionist such as DispatchLine takes your overflow calls, rebuild that forwarding on the new provider and test it. The walkthrough on how to forward your business line covers the common setups.
- Things plugged into the old line. Alarm panels, fax machines and card terminals that dial out over copper stop when the line is disconnected. Call the alarm company first.
- Outbound caller ID name. Ask the new provider whether it registers your business name for outgoing calls.
What does not break: your listings. Google, Yelp and the truck wraps still point at the right number, which is the reason to port instead of starting over. The rules behind that right are in the guide to number portability.
FAQ
How long does it take to port a phone number?
Under FCC rules a simple landline or landline-to-wireless port must be completed within one business day of a clean request, and other ports within four business days. Verizon quotes 4 to 24 business hours for mobile numbers coming to it and 2 to 10 business days for landline numbers. A rejection adds time.
Should I cancel my old phone service before porting?
No. Keep it active until the number works on the new service. A canceled number has to be reactivated before it can be ported, and the old carrier closes the ported line itself.
Does it cost money to port a number?
Verizon says it charges no fee to move a number to or from its service, though you still owe any device balance or early termination fee. Some gaining providers charge to bring a number in; Google Voice, for example, charges $20 to port a mobile number into a personal account.
Can I port only some of the numbers on my account?
Yes. Tell the new provider exactly which numbers to move and keep the rest with the old carrier. If one of the numbers leaving is the billing telephone number, call the old carrier first so it can move the remaining lines under a new main number.
Can I port a number that has already been disconnected?
Not while it is disconnected. Ask the old carrier to reactivate it, then submit the port again. Move quickly, because a disconnected number can eventually go to someone else.
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