What is a Letter of Authority? (LoA)

If you've ever moved your business broadband or phone lines, you've probably signed one without giving it much thought. Here's what it covers, what it doesn't, and why the small details matter more than you'd expect.

What a Letter of Authority does

Your provider will only discuss your account with you or with someone you've named. That's a good thing; it protects your business. But it means that when we ask your current provider for your contract end date, your monthly costs or what's running on your line, the answer is no until you've said it's fine.

An LOA is you saying it's fine, in writing. Once it's signed, we can compare deals based on what you actually have, not a best guess.

Switching business broadband or phone lines? You might sign two LOAs

With broadband and phone lines, there are often two different Letters of Authority involved. They do different jobs.

The first is the one you sign with us. It lets us see your current contract details so we can find the right deal.

The second comes from your new provider if you're keeping your phone number. Unlike mobiles, business landlines and VoIP numbers don't use a PAC code; instead, you fill in an LOA and usually supply a recent bill from your current provider. This one gives your new provider permission to ask your old one to hand the number over.

Same name. Different job. Knowing which one you're signing saves a lot of back and forth.

Switching energy or water? It's usually just the one: the LOA you sign with us.

Does signing a Letter of Authority commit you to anything?

Signing a Letter of Authority doesn't sign you up to a new deal. We can gather information, negotiate, and, where needed, give notice to your current provider, but we can't agree to a new contract without your say-so. You choose the deal. We handle the admin around it.

Why your LOA details need to match when porting a number

Every detail on a porting LOA needs to match your current provider's records exactly, including your legal business name, billing address and the service address for the number. Tiny differences, like "Ltd" on one and "Limited" on the other, are among the most common reasons a port gets delayed or rejected.

The easiest fix: have a recent bill to hand and copy the details straight from it. The form also needs signing by someone authorised to act for the business.

Keeping your number isn't a favour from your provider, either. Ofcom's General Conditions B3 and C7 set out the rules providers must follow when you ask to take your landline or mobile number with you.

What the 2027 PSTN switch-off means for your LOA

Openreach is retiring the UK's old copper phone network, the PSTN, on 31 January 2027. That affects every service running over copper lines, including ISDN, ADSL and FTTC broadband.

As a result, many businesses are moving to digital phone lines, and most want to keep the number their customers already know. That means a porting LOA. A single-line port can take around seven to ten working days, while more complex multi-line or ISDN setups can take several weeks. So if a move is on the cards, it helps to get the paperwork right the first time.

Do you need a Letter of Authority for energy and water?

Yes. LOAs aren't just a phone line thing. When we compare energy or water for you, your supplier needs your say-so before sharing your account details with us. Different essentials. Same idea.