Letter of Authorization (LOA) for Number Porting

A Letter of Authorization (LOA) is the signed form that lets your new phone provider ask your current carrier to release your number. It names the numbers to move, repeats your account details exactly as the current carrier has them, and carries the signature of someone authorized on the account. If any field disagrees with the current carrier's records, the port can be rejected.

This guide explains each field so you fill it in once and get it right.

Why the LOA exists

Number porting is initiated by the gaining provider, not by you calling the old carrier. The LOA is the gaining provider's proof that the account holder asked for the move. It protects you from unauthorized ports and protects the carriers from disputes.

The FCC's porting guide puts it plainly: contact the new company to start the process and provide your number and any additional information required. The LOA is that additional information, in writing.

The fields on a typical LOA

Every provider uses its own form, but the content is close to standard.

Field	What to enter	Where to get it
Business or account name	The name on the current account, exactly	Current bill
Authorized contact name	Person signing	Must be listed on the account
Service address	Where service is installed, including suite	Bill or Customer Service Record
Account number	Your account number at the current carrier	Bill
Port-out PIN / passcode	PIN set for porting	Ask current carrier
Billing telephone number (BTN)	Main number the account bills under	Bill
Numbers to port	Every number, 10 digits	Bill or portal
Full or partial port	Whether all numbers on the account move	Your decision
Requested port date	Preferred date (not guaranteed)	Your decision
Signature and date	Authorized signer	You

Business name

Use the name the carrier has on file, which is often your legal entity name rather than the brand you trade under. If the account was opened by a previous owner or under a former company name, fix that with the current carrier first or expect a rejection.

Service address

This is where the line is installed or registered, not your mailing address. For VoIP accounts it is often the address entered at signup. Include suite and floor exactly as the carrier lists them. When unsure, request a Customer Service Record.

Account number and PIN

Wireless carriers almost always require a port-out PIN or passcode, which is separate from your voicemail PIN. Many landline and VoIP carriers require one as well. If you have never set it, ask the carrier to create one.

Numbers to port

List every number you want to move, including ones you rarely think about: a fax line, a second location, an alarm panel or elevator line. If you leave a number off, it stays at the old carrier. If you include a number that is not on the account, the port can be rejected.

Full vs partial

A full port moves every number on the account. A partial port leaves some behind. If you are moving the billing telephone number but keeping other lines, the current carrier may require a new BTN on the remaining lines before it releases the port. Settle this with your current carrier before you sign.

Pre-signing checklist

• Name matches the bill character for character.
• Service address matches, including suite and ZIP.
• Account number is the account number, not an invoice number.
• Port-out PIN is current and confirmed with the carrier.
• Every number listed belongs to this account.
• Signer is the account holder or a listed authorized user.
• You know whether this is a full or partial port.
• A recent bill copy is attached if your new provider asks for one.

What happens after you sign

The gaining provider submits the port request with your LOA details. The losing carrier compares them against its records. If they match, both carriers agree on a Firm Order Commitment (FOC) date. If they do not, the losing carrier rejects the request with a reason.

The FCC requires simple ports to complete within one business day of a valid request (47 CFR § 52.35). Business ports with multiple lines or special configurations often take longer. See how long number porting takes for realistic expectations.

Common LOA mistakes that cause rejections

Twilio's porting help center lists incorrect name or address as the most common rejection reason, followed by incorrect PINs and requests from people who are not authorized on the account. In practice the same handful of mistakes show up again and again:

1. Using the trade name instead of the legal name on the account.
2. Mailing address instead of service address.
3. Old PIN after someone at the carrier reset it.
4. Numbers from two different accounts on one LOA. Each account needs its own LOA.
5. Signer not on the account, such as an office manager whose name the carrier does not have.
6. Pending orders or changes at the old carrier at the time of the port.

For fixes, see why number ports get rejected.

Businesses with several locations or carriers

If your numbers sit with more than one carrier, or under more than one account at the same carrier, prepare one LOA per account. Each losing carrier validates only its own records, so mixing accounts on one form invites a rejection for the whole batch. Submit them as separate port requests and track each FOC date on its own. Port the least critical numbers first if you want a low-risk test of the process before moving your main line.

Keep a copy

Save the signed LOA and the bill you used to fill it in. If the port is rejected, the reason code will point to a field, and you can compare against the exact document you submitted. If you ever face an unauthorized port, the LOA trail helps your provider and the carrier resolve it. The FCC warns about port-out fraud, so treat your PIN like a password.

LOA vs other porting documents

Document	Purpose	Who issues it
LOA	Your authorization to move the number	You sign; gaining provider supplies the form
CSR	The losing carrier's record of your account	Losing carrier
FOC	Confirmed date the number moves	Agreed between carriers
Bill copy	Supports the details on the LOA	You provide

Porting your number to Callata

Callata ports numbers in for free. To start, email [email protected] with the numbers you want to move and a recent bill, and support will tell you exactly what to sign. Keep your current service active until the port completes. You can create your account now, set up routing and 911 on a temporary local number, and have everything ready when your number arrives. Read the full step-by-step porting guide for the rest of the process.