Door entry phone systems are changing

The Telguard Analogue door entry phone system was our first telephone intercom system solution, launched back in 1992. Having obtained full BABT approval this year, our units were the first to be authorised for official connection into BT's exchanges.

Door entry phone systems are still extensively in use throughout the U.K. and have proven to be a reliable access solution for many years. However, these days are coming to an end.

BT has recently announced that they will stop taking orders for new ISDN (Integrated Service Digital Network) and PSTN (Public Switched Telephone Network) lines, with a view to switching off and deactivating the networks completely in 2025. BT plan to replace the two networks with VoIP (Voice Over Internet Protocol), which does not run over traditional copper lines but utilises an active internet connection instead.

What does this mean for your telephone entry system?

BT’s modernisation will result in any apparatus or services connected to ISDN or PSTN lines ceasing to work when the lines they are connected to are switched off.

For Telguard customers with units connected directly to PSTN lines, this means that these units will stop working. Customers whose units are connected to a PABX, PBX or VoIP system already by using an ATA (Analogue Terminal Adaptor) will not be affected and their door entry phone systems will work as normal.

Why are BT making the switch?

VoIP has many advantages over PSTN and ISDN for domestic and business users, including:

  • Faster provision of new lines.
  • The reduction of physical lines needed can result in cost savings.
  • VoIP is more scalable and flexible.

Will I need a new door entry system?

Not necessarily. Telguard has developed a convenient and cost-effective upgrade path to transform your analogue Telguard model to 4G in line with our lifetime product support objective. If no 4G network is available they will work perfectly well on available 3G or 2G networks.

It may also be viable to connect the analogue unit to the new VoIP line using an ATA.

Additionally, Telguard is working on a SIP solution that will work with a VoIP line. This is a work in progress but should be available by Q2 2022.

If you are concerned that your door entry phone system may be affected by BT’s switch to VoIP, contact BT to find out whether your local PSTN network will be affected. In some remote locations it may not be as cost-effective to completely turn off the network and replace it with VoIP, so request the information for your area.

If you have a Telguard system and would like more information on whether this will affect you or the customer support solutions we can offer, don’t hesitate to get in touch.

For more information on new intercom access systems, or for help with your existing Telguard system, call us on , or visit For more information on new intercom access systems, or for help with your existing door entry phone system, call us on +44(0)1306 710120 to speak to a member of our friendly team. Alternatively, visit our Contact Page. We look forward to hearing from you!

intercom phone system