What Is a Letter of Authorisation (LOA) for Phone Number Porting?

What Is a Letter of Authorisation (LOA)?

An LOA is written permission to transfer a phone number. It names the numbers being moved and the account they sit on. Your new provider uses the signed LOA as part of the porting request, so your current provider can check the request is genuine.

Why Do You Need an LOA to Port a Number?

Moving a number changes someone’s phone service, so providers need proof that the owner agrees. The LOA is that proof. It stops a number being moved without the account holder’s knowledge, and it gives both providers a record of who approved the request.

What Information Does an LOA Include?

Use the current version of the form and fill in every field. Some providers also ask for a company registration number and a contact email.

Who Can Sign an LOA, and Can It Be Signed Electronically?

It must be signed by the account holder, or someone authorised to act for the business, such as a director or owner. An employee without authority on the account shouldn’t sign it.

Whether you can sign electronically depends on the provider. Some accept a digital signature with an audit trail, while others only accept a hand-signed copy. Check with your new provider before you sign, as the wrong type of signature can lead to a rejection.

How Long Is an LOA Valid?

It varies by provider. Some UK providers treat an LOA as valid for around six months from the date on it, while others set a different limit. Check the validity period before you sign, and avoid leaving the LOA too long before the request goes in.

How Does an LOA Fit into the Number Porting Process?

The signed LOA is an important part of the porting process. This is the usual order:

1. Your new provider confirms your numbers can be ported.
2. You receive the LOA and check the details.
3. An authorised person signs it and returns it.
4. Your new provider submits the request to your current provider.
5. Your current provider accepts or rejects the request.
6. A port date is confirmed and your numbers move.

Keep your old service active until the port is complete. Our number porting team can help.

How Long Does a Number Port Take Once the LOA Is Submitted?

For a standard port away from BT, it usually takes two to four weeks, depending on your setup and how accurate the details are. Other providers and number types can differ, and a request with matching details usually moves faster than one that needs corrections.

Your new provider should confirm a port date once your current provider accepts the request. Our guide to porting a number away from BT covers the stages in more detail.

Do You Need a Separate LOA for Multiple Numbers or a Block of Numbers?

Not always. One LOA can usually cover several numbers held on the same account with the same provider. You will normally need a separate LOA for each provider or account.

For a block of numbers or a DDI (Direct Dial-In) range, list the full range and the main billing number, as ranges often need to port together. A longer list can go on a continuation sheet or spreadsheet if your new provider accepts one. Practice differs, so ask before you sign.

Why Do LOAs Get Rejected?

The most common reasons are simple paperwork errors:

• Name or address doesn’t match your current provider’s records
• Wrong main billing number or account number
• LOA incomplete, unsigned, out of date or signed by someone without authority
• Signature type not accepted, such as a digital signature where a hand-signed copy is needed
• The number is inactive or not in service
• A linked alarm or security line with no separate order
• Missing numbers from an ISDN range or DDI block

To fix it, compare the LOA with your latest bill, correct the error and resubmit.

Does Porting a Number Cancel Your Old Contract?

Porting moves your number but doesn’t end your contract. You can usually port while still in contract, but early termination charges may apply, so check your terms and confirm any notice period with your current provider.



Porting a fixed-line number usually ceases the original line, and linked services such as broadband can go with it. Don’t cancel the service until the port is complete, or you could lose the number.