The most likely explanation is that you're trying to register with a service that we don't support with an online account.
Services you CAN register online
- Phone Line
- OneBill (including mobile and private circuits)
These are the only services that you can currently register for an online account. If you're trying to register anything but one of these, you won't be able to open an account.
Services that you CANNOT register online
- Mobile (unless it's part of a OneBill account)
- Private Circuits (unless it's part of a OneBill account)
- Internet Teleworker
- BT Wi-fi (also known as Openzone)
- SIP Trunking