PSTN Switch-Off January 2027 — UK Business Migration Guide
PSTN & ISDN SWITCH‑OFF — JANUARY 2027
The PSTN switch‑off is real. Every UK business is affected.
The UK’s PSTN and ISDN networks switch off on 31 January 2027. Any business still using copper‑based phone lines, ISDN, analogue alarms, lift phones, fax lines, dial‑up payment terminals or broadband over PSTN is affected—whether they realise it or not.
The remaining time is for migration, not procrastination. Businesses that leave this until late 2026 will compete for engineer availability and number ports.
3CX Platinum Partner · RIPE NCC Member · UKAS ISO/IEC 27001:2022 Certified · SIP & Number Porting Specialists
What is actually changing
The UK’s traditional telephone network—the Public Switched Telephone Network (PSTN) and Integrated Services Digital Network (ISDN)—is being permanently decommissioned. After 31 January 2027, Openreach will stop carrying voice and signalling traffic over copper. Any service that depends on PSTN or ISDN will stop working.
The replacement is IP‑based communication delivered over fibre, fixed‑wireless or mobile networks: VoIP, SIP trunking, hosted phone systems, IP‑based alarms and lift phones, and modern payment terminals. The technology is mature and widely deployed, but migrating properly takes time and planning.
The systems most businesses overlook
The phones are obvious. The hidden failures happen elsewhere.
Burglar alarms and signalling
Alarm systems using PSTN, Redcare or older GPRS signalling will stop reaching alarm receiving centres. That puts insurance compliance and police response at risk.
Lift emergency phones
Lift phones are a legal requirement under EN 81‑28. Most are PSTN‑based and will fail silently, leaving building owners exposed to liability.
Payment terminals
Legacy card terminals and dial‑up fallbacks—still common in retail and hospitality—depend on PSTN and will stop working.
Fax machines
Still used in legal, healthcare and logistics environments. Fax over PSTN ceases entirely; cloud fax or IP alternatives are required.
Broadband over PSTN (FTTC/ADSL)
Copper‑based broadband is being migrated to FTTP, SOGEA or wireless alternatives—often separately from voice services.
Door entry and intercom systems
Door entry and gate intercoms connected to analogue phone lines are often missed because nobody has touched them for years.
A proper PSTN migration assessment covers all of these. We regularly see emergencies caused not by the phone system, but by a missed alarm, lift phone or back‑office line.
The biggest risk isn’t the phone system—it’s the decade‑old devices nobody remembers until the day they fail.
The migration paths
Migration isn’t one decision. Different systems move in different ways.
Phone systems
- Hosted VoIP / cloud phone systems — fully managed, scalable, modern features.
- 3CX (cloud or on‑premises) — feature‑rich, cost‑effective, strong control; we are a 3CX Platinum Partner.
- SIP trunking — retain a modern PBX while replacing ISDN with IP trunks.
- Microsoft Teams Phone — suitable where Teams already drives collaboration.
Alarms and signalling
- Dualcom IP, Redcare Advanced and equivalent IP‑based signalling solutions, coordinated with alarm contractors.
Lift phones
- 4G or IP lift phone units with built‑in EN 81‑28 compliance.
Broadband and connectivity
- FTTP where available.
- SOGEA where FTTP is not yet deployed.
- Fixed‑wireless or mobile broadband where wired options are impractical.
Why acting now matters
- Engineer capacity tightens through 2026. Late movers will struggle to secure dates.
- Number porting takes time. Expect 2–6 weeks under normal conditions.
- You will discover forgotten lines. Finding them early avoids frantic fixes later.
Frequently asked questions — PSTN switch‑off
31 January 2027. The original 2025 deadline was extended once. There is no indication of further extensions.
Phones, alarms, lift phones, dial‑up card terminals and PSTN‑dependent broadband will stop working.
Yes. Geographic numbers can be ported to IP services. Plan this early.
IP phones require local power and connectivity. Backup power or mobile failover is planned where required.
Yes. PSTN migration is delivered as a structured project by a 3CX Platinum Partner and ISO 27001‑certified MSP, not a box‑swap exercise.
Get a PSTN migration scoping for your business
Tell us about your users, phone systems and any devices connected to phone lines. We’ll scope properly and produce a fixed‑price migration plan.
Or call us directly: 01452 701355
Business enquiries only · No obligation · Response within one business day.
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