You signed a Letter of Authority naming Hello Bill Limited, the company behind helloBill. It lets Bill deal with the providers you chose on your behalf — contacting them, requesting and providing account information, registering you as the new occupant, notifying your council and chasing progress.
Anything with a financial consequence — moving to a new supplier, entering a contract, cancelling, or setting up a payment — you approve separately at the time, on its own screen.
The authority expires when your set-up completes or after 90 days, whichever comes first. You can revoke it any time at [email protected].