How to Port a Business Phone Number, Step by Step

Porting moves your existing business phone number from one provider to another without changing the number your customers dial. You request the port from the new provider, sign a Letter of Authorization (LOA) with details that exactly match your current account, and keep the old service active until the new provider confirms the number has moved.

That is the whole process in one paragraph. The rest of this guide covers the details that decide whether your port finishes in a day or stalls for weeks.

What porting is, and what it is not

Local Number Portability (LNP) is the FCC requirement that lets you keep a number when you switch carriers within the same area. It works between landline, wireless and internet-based (VoIP) providers. The FCC consumer guide on porting states that you can keep your number "if you're switching service providers and remaining in the same geographic area."

Porting is not:

• Call forwarding. Forwarding leaves the number at the old carrier and sends calls elsewhere. You keep paying the old carrier, and texts usually do not follow. See how call forwarding works for businesses if you only need a stopgap.
• A transfer of your account features. Voicemail boxes, greetings, call history and hunt group settings stay behind. You rebuild them at the new provider.
• Automatic for texting. Business texting on a ported local number still needs carrier registration at the new provider. See what 10DLC is.

Step 1: Confirm the number can move

Before you sign anything, ask the new provider to run a portability check on every number you want to move. Two things can block a port:

1. Geography. Landline and VoIP numbers are tied to a rate center. If the new provider has no coverage in that rate center, the number cannot be ported to it.
2. Rural exemptions. The FCC notes that some rural wireline carriers hold state waivers from porting obligations.

Toll-free numbers follow a different system, managed through RespOrgs rather than local number portability. If you have an 800-type number, read local vs toll-free numbers first.

Step 2: Gather your account details

Most rejected ports come from information that does not match what the losing carrier has on file. One large carrier's help center lists incorrect name or address as the most common rejection reason. Pull a recent bill and collect:

Item	Where to find it	Common mistake
Account holder name	Top of your bill	Using a DBA when the account is under the legal entity name
Service address	Bill, or ask the carrier	Using the mailing address instead of where service is installed
Account number	Bill	Using an invoice or order number
Port-out PIN or passcode	Request from current carrier	Assuming your voicemail PIN is the port PIN
Billing telephone number (BTN)	Bill	Forgetting it on multi-line accounts
Full list of numbers	Bill or carrier portal	Leaving out fax or alarm lines
Authorized signer	Account records	Signer is not listed on the account

If you are unsure what the carrier has on record, ask for a Customer Service Record. Our guide to the CSR and why it matters explains how to request one.

Step 3: Decide full port or partial port

A full port moves every number on the account, and the old account typically closes. A partial port moves some numbers and leaves others behind, so the old account must stay open for the remaining lines.

Partial ports are where many business ports go wrong. If the number you are moving is the billing telephone number, the losing carrier may require you to assign a new BTN to the remaining lines before it releases the port. Ask your current carrier about this before submitting.

Step 4: Sign the Letter of Authorization

The LOA is your written permission for the new provider to request the number on your behalf. It lists the numbers, your account details and an authorized signature. Read what goes on an LOA for a field-by-field breakdown.

Sign it as the person listed on the account. A port submitted by someone the losing carrier does not recognize as authorized is a stated rejection reason.

Step 5: Wait for the FOC date

After the new provider submits the request, the losing carrier validates it. If everything matches, the carriers agree on a Firm Order Commitment (FOC) date, which is the day the number moves.

The FCC requires simple ports to complete within one business day of a valid request (47 CFR § 52.35). A simple port is generally a single line without complex switch features. Business accounts with multiple lines, hunt groups, ISDN or Centrex often count as complex. Twilio's published guidance says US ports typically take 5 to 15 days and can take four weeks or more when a carrier rejects the request. For a detailed breakdown, see the number porting timeline.

Step 6: Prepare for port day

Before the FOC date:

• Set up users, call routing and voicemail at the new provider so calls have somewhere to go.
• Record new greetings. See business voicemail greeting scripts.
• Register the 911 address for the number at the new provider. See E911 for VoIP.
• Tell your team the port window so nobody panics if a call rings on the old system that morning.
• Do not schedule the port on your busiest day.

Step 7: Test, then cancel

After the port completes:

1. Call the number from a mobile phone on a different carrier. Confirm it rings at the new provider.
2. Call from a landline if you can. Carrier databases can update at slightly different times.
3. Make an outbound call and check the caller ID.
4. Leave a voicemail and confirm it arrives.
5. Check that inbound texts arrive, if texting is enabled.

Only after these pass should you cancel any remaining service at the old carrier. For a full port, confirm the old carrier closed the account so you are not billed for a line you no longer have.

If the port is rejected

A rejection is a reply, not a dead end. The losing carrier returns a reason code, usually something like a name, address, account number or PIN mismatch. Fix the specific field and resubmit. Our list of why number ports get rejected covers the common codes and fixes.

Protect the number from unauthorized ports

Port-out fraud happens when someone else ports your number away using your account details. The FCC warns about this risk. Set a port-out PIN with your carrier, limit who on your team knows it, and ask any new provider whether it offers port-out protection.

Porting a number to Callata

Callata ports existing numbers in for free. Email [email protected] with the numbers you want to move and the details from your current bill, and keep your old service active until the port completes. While you wait, you can sign up, pick a temporary local number, and set up business-hours routing, voicemail and 911 so everything is ready on port day. The plan is $99 a month for up to five users with up to three local numbers included; each additional user is $20 a month.