Our current provider is Sky.
Its quite possible the issue is with the Sky exchange equipment.
As this is a BT Retail Customer Forum, you would be best to post on the Sky Customer Forum for advice. They may suggest trying a different phone to prove whether its the phone, or the Sky line equipment.
The other option would be to contact the product helpdesk.
Within the 12 month
guarantee period
Prior to returning your product,
please read the Help section
beginning on page 62 or contact
the Premium Phone Helpline on
0800 145 6789. Additional
answers to frequently asked
questions are available from
bt.com/producthelp
Outside of the 12 month
guarantee period
If your product needs repair after
the guarantee period has ended,
the repair must meet the approval
requirements for connection to the
phone network.
We recommend that you contact
BT’s recommended repair agent
Discount Communications on 0800
980 8999 or a local qualifed
repairer.
It could be an issue with the CLI (Calling Line Identification) signal being corrupted and the phone unable to decode it.