Incompatible BT product | Description | Solution |
| Previous ISP marker or tag | When you cease (NOT migrate) service from one ISP, their marker is left on the line for a few days or weeks. | Call the old ISP's cancellations department and have them confirm that your bill is paid. Call the new ISP's provisioning department and have them pester BT Wholesale to confirm that no marker is present. If you do not know which ISP has their marker on the line, you may call the Ofcom Contact Centre on 0207 981 3040 to ask. |
| DACS installed | Allows two ordinary phone lines to be squeezed down a single copper wire as explained here. | Ask BT to invest in the infrastructure by laying more cables. Consider having a satellite broadband delivery rather than DSL. |
| Non-BT lines | For example if you pay line rental to a provider other than BT | |
| New BT line | It takes a few days or weeks to enable a line for broadband | Call your BT sales operative and ask when you will be able to apply for broadband |
| Existing DSL service | Only one ISP can supply broadband concurrently. | Ask your existing supplier for a MAC key and pass it to the new supplier. |
| Subscriber Private Metering | Allows customers to monitor the cost of telephone calls as they progress. | Removal of service followed by re-application or install a new telephone line for broadband. |
| Call restrictions | Some line features (e.g. incoming calls only) are incompatible with broadband | Cancel such services. |
| 30k Loop | A service that lets you move your telephone number outside the range served by the original area code. | Install a new telephone line for broadband. |
| Leased lines or non-BT line | Dedicated private connection to the Internet | Install a new telephone line for broadband. |
| ISDN (all types) | Digital telephone service, such as BT Home Highway, providing faster Internet connection than traditional analogue telephone systems. | The new ISP will arrange for a BT engineer to convert your ISDN line to a broadband enabled phone line. This will cost about £50 and is paid directly to BT. |
| redcare | A BT security alarm system that contacts the emergency services using a telephone line based signal. | Contact your alarm system supplier and ensure that a redcare Modem Compatibility Device is fitted, then re-order broadband. |
| red abc, redcare isdn and redline | Variants of the redcare service that provide monitoring and management information. | Remove service and re-order broadband or order a new phone line for broadband. |
| FeatureNet 5000 services | Virtual phone management system that provides companies with telecommunication and data services over a Virtual Private Network (VPN). | Install a new telephone line for broadband. |
| Meter Pulse Facility | Virtual phone management system that provides companies with telecommunication and data services over a Virtual Private Network (VPN). | Install a new telephone line for broadband. |
| PBX switchboards or AUX lines | Telephone systems and services commonly found in medium to large businesses. | Install a new telephone line (not on the PBX/AUX) for broadband. |
| Caller Display Unit – CD 50 and CD 1500 | Device used to display the number of incoming calls. | Remove device then re-order broadband or install a new telephone line for broadband. |
