When an incompatible product is identified on a line we cannot place an ADSL order on the line until that product is removed. BTWholesale will not inform us what the incompatible product is exactly for data protection reasons. In all cases the EU must contact their PSTN line supplier (e.g. BT Retail) to find out what the incompatible product
is (if they do not already know) and arrange for its removal if they still wish to go ahead with ordering ADSL on the line.

If, after contacting their PSTN supplier, the PSTN supplier insists that the line is a normal analogue PSTN line with no other extra products on it, then we suggest contacting the Tags on line team on 0800 169 9576. They will be able to let the EU know why an order cannot be placed.
 

A standard BTW PSTN analogue line is required for ADSL. Certain BTW services and/or configurations are NOT compatible with ADSL, these include:-
 
None BTW Telephone Line 
Alarm Lines Multi Auxiliary Working Lines
Analogues Direct Dialling In (DDI)
BTW Data Stream
BTW Video Stream
Caller Redirect
Feature net
Internet Callers
ISDN2e / ISDN30e
Line concentrators
Lines served via TPON
Low Loss lines
Low User Scheme lines (only BT Retail)
Meter Pulse Facility
Night Busying
Out of Area lines
Payphone Lines
PBX Switchboard
Privacy Sets
Pulse Metered Line
Redcare Alarm Monitoring
Surftime
Temporary Lines

Please note that this is a list of the most common PSTN Incompatible Products and is not exhaustive.