In 2019, it was announced that the Integrated Service Digital Network (ISDN) and Public Switched Telephone Network (PSTN) would be switched off in December 2025.

With 6 years until that date, there was no major rush from businesses to change. Fast forward 4 years, and the more forward-thinking businesses are now starting to make their contingency plans – because as of 2023 – customers will no longer be able to purchase new lines, with the complete switch off taking place in 2025.

Prepare your business for the BT ISDN & PTSN switch off | Anglia Tech (

What is ISDN?

Integrated Services Digital Network is the international standard for end-to-end digital transmission of voice and signalling. The latest generation ISDN2e is the standard basic two channel ISDN service available from Mainstream Digital. ISDN2e is available from 2 lines upwards, making it suitable for small businesses.

ISDN 30e

ISDN30 is the European standard for digital connection to ISDN Primary rate service and is the equivalent of up to 30 exchange lines delivered to your premises by fibre cable and connected to the PBX. ISDN30 is available from only 8 lines upwards, making it suitable for a wide range of businesses.

What can it do for me?

These 64 kbps digital exchange lines give high speed connections for clear voice transmission, with fast call set-up and near instantaneous call connection, saving time and money with cost effective public switched telephone networks call rates.

Contact Our Team

Contact Anglia Technology to discuss your cloud-based telephone system requirements and we’ll guide you to a solution that suits you and your business.