The PSTN Switch Off: what UK businesses need to know

The UK's traditional copper telephone network — the Public Switched Telephone Network (PSTN) — is being retired by Openreach on 31st January 2027. Every business still relying on analogue phone lines, ISDN circuits or ADSL/FTTC broadband over copper needs to migrate to a fully digital, IP-based service before then.

Why is the PSTN being switched off?

The copper-based PSTN network is decades old and increasingly expensive and difficult to maintain. Openreach is retiring it in favour of a fully digital, fibre-based network, moving all voice traffic onto Voice over IP (VoIP).

Key dates

• Original deadline: December 2025 — since revised.
• Current deadline: 31st January 2027, when the PSTN will be fully retired and all copper-based services will stop working.
• Stop-sell in effect: in most exchange areas Openreach has already stopped taking new orders for copper-based services, meaning many businesses can no longer buy or amend PSTN, ISDN or ADSL/FTTC connections.
• No further delay to the January 2027 date is currently expected.

What does this affect?

• Analogue and digital phone lines, and ISDN2/ISDN30 business phone systems.
• ADSL and FTTC broadband, which run over the same copper infrastructure.
• Other devices that rely on a phone line, including alarm systems, lifts and payment terminals.

How Stream can help you migrate

Getting ahead of the PSTN switch off means moving your business onto resilient, future-proof connectivity and communications now, rather than waiting for a deadline-driven scramble. Stream can help with:

• Full Fibre & SOGEA broadband — replacing ADSL/FTTC with a fibre connection built for the digital switchover.
• Fibre Ethernet Leased Lines — dedicated, resilient connectivity for larger sites and critical applications.
• VoiceLogic cloud VoIP & SIP Trunks — moving your phone system off legacy lines and onto our unified communications platform.
• Multi-network mobile backup — keeping you connected even if a fixed line is affected during the transition.