Update, 30 September 2026: the national switch-off date has moved. BT and Openreach now plan to retire the PSTN and ISDN on 31 January 2027, and no new analogue lines can be ordered. The dates below have been updated; the advice has not changed.
Ready or not, it is happening.
In 2017, BT announced that the Public Switched Telephone Network (PSTN) and the Integrated Services Digital Network (ISDN) would no longer exist.
“Why?” I hear you say.
Many phone lines still use copper cables, and both the PSTN and ISDN are struggling to meet the demands of today’s business environment.
With the switch off now set for 31 January 2027, fixed telephone networks will be replaced with digital systems such as IP telephony and Voice over Internet Protocol (VoIP).
This is ultimately a good thing, and I have listed a few details below to help you understand it.
Will my phone lines stop working?
Yes. All analogue, ISDN2 and ISDN30 platforms will be retired by 31 January 2027. If your business uses one of these legacy platforms for its telephone calls, you need a plan in place for the switch off. Keep your business telecoms unaffected by changes to the wider network with high-quality internet, SIP-compatible telephone systems and a robust data network infrastructure.
Does this just affect my phone lines?
No. Any technology running over your current PSTN or ISDN lines will stop working. This may include alarm systems, lifts and door entry systems, to name a few.
What should I do?
Start planning now. If you are not ready for the switch off when it happens, your business will suffer operational issues.
Your plans should include the following:
- Seek advice via an on-site infrastructure audit.
- Understand if your current telephone system is suitable for your requirements moving forward. For example, are you gearing up for hybrid or remote working?
- Some systems may be ready for the switch off, but check whether you need to upgrade to an internet-based solution to replace the current PSTN or ISDN.
- You may need to upgrade to an IP-based solution for compatibility. If you need to keep legacy equipment, you may need analogue converters.
- Moving to IP lets you use the latest collaboration tools. For example, you can integrate your telephone system with your Microsoft 365 environment, allowing you to make and receive calls from one application.
Is IP better than PSTN and ISDN?
The quick answer is yes. IP telephony opens up the possibilities of cloud-based communication, with higher-quality audio, resilience, redundancy and scalability.
What is best for my business after PSTN and ISDN?
There are many options, from an on-site phone system with SIP trunking to a hosted cloud-based telephone system with IP handsets. We would work with you to understand your requirements.
You may need to upgrade your internet connection to make sure it has the capacity for all your business technology.
How much will this cost?
This depends on your requirements and current infrastructure. However, switching to a cloud-based system can save money in the long run.
Finally
Being prepared now will prevent a last-minute panic, as 31 January 2027 is just around the corner. With so many options available, talk to our experts to find the best solution for you.
To get yourself and employees ready for the switch off, talk to us or call 01642 661888.