First off, let’s clear up some of these acronyms and names.
PSTN is the Public Switched Telephone Network. This is the wired (copper) infrastructure that has long been used for telephone services (first deployed in the United Kingdom in the 1800s), and was later expanded to provide internet access.
ISDN is an Integrated Services Digital Network. This is the system that many business phone systems have been built upon for many years, and it uses the same copper cabling as the PSTN.
Optical Fibre is modern cabling used to transmit data. Rather than having a metal core which suffers from various limitations (maximum distance, interference and signal degradation), it uses light instead (does anyone remember GCSE Physics and “total internal reflection”?!).
Fibre to the Cabinet (FTTC) is still a commonplace internet service in many homes and businesses. It uses the PSTN copper network to connect your premises to the local cabinet, with optical fibre used from the cabinet onwards.
Fibre to the Premises (FTTP) is an internet service being adopted by an increasing number of homes and businesses. It does not use the PSTN at all, instead relying on optical fibre directly into your premises, delivering a vastly superior and future‑proof service.
PSTN Switch‑Off
In response to the growing recognition that it is no longer fit for purpose, the UK’s legacy copper telephone network is being switched off.
The original switch‑off date of December 2025 has now been formally revised. The final withdrawal of PSTN and ISDN services will take place on 31 January 2027.
This change allows more time to safely migrate vulnerable users and services such as telecare, but the direction of travel has not changed: the PSTN is being permanently retired.
Key milestones to be aware of:
- The programme was first announced in 2015.
- Many areas have already entered “stop‑sell”, where new PSTN‑based services are no longer available.
- New PSTN and ISDN orders have effectively stopped, with providers only offering digital alternatives.
- All remaining PSTN and ISDN services will cease on 31 January 2027.
Who will be affected?
If you currently use any of the following, you will need to move to an alternative solution:
- Traditional landline telephones plugged directly into a phone socket.
- Internet services delivered over PSTN copper lines, including FTTC and ADSL.
- ISDN‑based business phone systems.
This applies to both business and residential users. Home internet and telephone services are just as affected as business phone systems.
What should I do?
Start planning now. By adopting one of the growing number of optical fibre broadband services, you will not only be ready for the PSTN switch‑off but also benefit from a faster, more reliable connection.
Modern IP‑based telephony (VoIP) runs over your internet connection, removing reliance on ageing copper infrastructure and unlocking far greater flexibility and resilience.
What are my telephone system options?
There is now a wide range of digital telephone systems available, all delivered over your internet connection. These can range from:
- Simple setups using familiar desk handsets.
- Fully cloud‑hosted phone systems.
- Unified communications platforms such as Microsoft Teams, which combine calling, chat and video meetings into a single solution.
These platforms are more scalable, easier to manage and better suited to modern working practices.
What if I can’t get Optical Fibre?
Don’t worry. The rapid increase in infrastructure investment has significantly improved coverage, even in traditionally rural or hard‑to‑reach locations. Availability is expanding all the time.
Where fibre is not yet viable, alternative connectivity options include 4G and 5G broadband, where your router uses a SIM card in much the same way as a mobile phone. For many businesses, this already provides more than enough performance and resilience.
Next Steps
Our team are experts in recommending efficient, reliable and future‑proof telephony solutions. We’ll take the time to understand your requirements and identify the best options available to you.
