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UK landline switch off confirmed · 31 January 2027
UK PSTN Switch Off 2027:
Move Your Business Phones Without Disruption
The UK’s traditional PSTN and ISDN phone services are being retired by 31 January 2027. If your business still depends on analogue landlines, ISDN circuits or equipment connected to a traditional phone socket, now is the time to prepare.
Time until the PSTN switch off
31 January 2027 · copper network goes silent
Over 2.8 million lines are still on PSTN. More than half a million serve business premises. Don't be last to move.
Trusted by growing businesses across UK
Why this matters
What is PSTN switch off, and why should you care?
Public Switched Telephone Network (PSTN) is copper-wire network that has carried UK landline calls since Victorian times. It's now obsolete: spare parts and engineering skills are scarce, faults are rising, and it can't support modern digital communication. That's why BT Group and Openreach, with oversight from Ofcom, are retiring it for good on 31 January 2027, along with ISDN and every service that runs over it.
lines still on the PSTN as the final countdown begins (Openreach, 2026)
of those lines serve business premises that must migrate before the deadline
UK businesses have at least one essential service that relies on the PSTN
increase in customer hours lost to PSTN faults in a single year. The network is failing
Who is affected?
Every home and business with an analogue landline, ISDN2/ISDN30 line, or copper-based broadband (ADSL/FTTC). If your phones plug into a wall socket rather than internet, landline switch off affects you.
It's not just phones
Card machines, door entry systems, lift lines, CCTV, fire and intruder alarms, telecare devices and fax all commonly run over PSTN lines. Each needs digital replacement or IP-ready upgrade.
What replaces it?
VoIP carries voice over broadband. It is delivered through cloud phone system (hosted PBX) like Calilio, or SIP trunks for businesses keeping on-site PBX. Full fibre broadband replaces copper internet.
Cost of waiting
What happens if you do nothing?
When your exchange is switched off, PSTN lines don't wind down gracefully; they simply stop. Here's what that looks like for unprepared business.
Missed calls, lost revenue
Dead lines mean every enquiry, booking and order call rings into silence, and callers rarely try twice. They ring a competitor instead.
Operational disruption
Forced, last-minute migration means downtime, rushed staff training and no time to test. Planned moves take days; emergency ones take weeks.
Emergency calling at risk
Lift alarms, telecare units and 999-critical lines connected to dead copper can fail silently, creating safety and compliance liability.
Stranded legacy hardware
On-premise PBX kit, analogue handsets, fax machines and PDQ terminals built for copper become expensive paperweights overnight.
Rising legacy charges
Openreach confirmed tiered price increases on legacy line rental. Staying on copper now means paying premium for service with expiry date.
Customers lose trust
Unreachable business looks closed. Days of dead phones damage reputation that took years to build.
Key dates
PSTN switch off timeline
Switch off isn't single event. It's phased retirement already well under way. Select milestone to see what it means.
Exchange-by-exchange migration
Openreach is retiring copper services exchange by exchange, with stop-sell now covering well over 1,000 exchanges and millions of premises. Your lines can be switched off before the national deadline, depending on when your local exchange migrates.
Get ready
Your PSTN migration checklist
Ten steps to zero-downtime switch. Work through them yourself, or book demo and Calilio's migration team runs whole list with you.
Get guided version- 01Inventory every line and deviceList all phone lines, fax machines, alarms, lifts, card terminals, door entry and telecare units, and anything plugged into a phone socket.
- 02Assess your broadbandVoIP runs over your internet connection. Check speed and reliability; consider upgrading to full fibre (FTTP) or SOGEA if you are on ADSL/FTTC.
- 03Audit your current phone setupNote your numbers, call flows, hunt groups, voicemail and opening-hours routing so nothing is lost in translation.
- 04Check device compatibilityDecide what to keep: IP desk phones, analogue adapters (ATAs) for legacy devices, or softphone apps on existing mobiles and laptops.
- 05Confirm internet readinessTest bandwidth headroom and jitter at peak times. A single HD VoIP call needs ~0.1 Mbps; quality of service matters more than raw speed.
- 06Plan staff trainingBook short sessions on the new apps and features. Most teams need under an hour with a modern cloud phone system.
- 07Test emergency and critical callsVerify 999/112 calling, alarm lines and lift phones on the new digital service, with battery backup where a line is safety-critical.
- 08Port your numbersSubmit your number porting request early. Porting typically takes 10–15 working days and your old lines keep working until the port completes.
- 09Run a parallel test periodRoute a subset of calls through the new system first. Confirm call quality, routing and integrations before full cutover.
- 10Go live, then decommissionSwitch all traffic to the cloud system, monitor the first week closely, and only then cancel legacy contracts and remove old hardware.
Why Calilio
More than a replacement: an upgrade
Moving off PSTN isn't avoiding shutdown only. Cloud phone system gives you tools copper line never could.
Cloud phone system
A full hosted PBX in your browser and pocket. It requires no server room, engineer visits or copper.
AI-powered insights
Live transcription, sentiment analysis and AI call reports on every conversation, which is impossible on an analogue line.
Call analytics
Real-time dashboards for volumes, wait times and agent performance across every site and team.
Global numbers
Local, mobile and toll-free numbers in 100+ countries. Expand without opening an office.
CRM integrations
Connect your CRM and helpdesk so every call lands with context and logs itself automatically.
Work from anywhere
Softphone apps for desktop and mobile keep remote and hybrid teams on the business number.
Call recording
Compliant, searchable recording with retention controls, ready for FCA, HIPAA-grade and internal QA needs.
Scales with you
Add a user, a department or a whole new location in minutes. Pay only for the seats you use.
UK migration support
A named specialist plans your port, tests your setup and stays with you through go-live, with 24/7 support afterwards.
Compare your options
Traditional PSTN vs On-Premises PBX vs Calilio
| Capability | Traditional PSTN line | On-prem PBX | Calilio Cloud Phone |
|---|---|---|---|
| Works after 31 Jan 2027 | ✕ Switched off permanently | Only with SIP trunk upgrade | ✓ Fully digital, future-proof |
| Upfront hardware cost | Low, but stranded at switch off | High: PBX, cards and cabling | ✓ None; works on existing devices |
| Setup time | No longer available (stop sell) | Weeks, engineer on site | ✓ A few hours, fully remote |
| Remote & hybrid working | ✕ Tied to the wall socket | Limited, VPN complexity | ✓ Any device, anywhere |
| AI transcription & analytics | ✕ Not possible | Expensive add-ons | ✓ Built in |
| Scaling up or down | New line install per channel | New hardware cards | ✓ Add a seat in minutes |
| Maintenance | Ageing network, rising faults | Your responsibility, including support contracts | ✓ Handled in the cloud, 99.9%+ uptime |
| Ongoing cost trend | Rising legacy line charges | Maintenance + licence renewals | ✓ Predictable per-user pricing |
How migration works
From copper to cloud in seven guided steps
Named Calilio migration specialist runs every step. Most businesses go live within two weeks; old lines stay active until moment your numbers port.
Assessment
We map your lines, numbers, devices and call flows, and check your broadband is VoIP-ready.
Planning
You get a written migration plan: what moves when, what needs replacing, and a zero-downtime cutover date.
Number porting
We submit and manage the port of your existing numbers. Your old lines keep working throughout.
Setup
Users, call flows, IVR menus, voicemail and integrations are configured to mirror, or improve on, your current setup.
Testing
Calls run in parallel on the new system. We verify quality, routing, emergency calling and every integration.
Go live
Numbers cut over at an agreed quiet moment. Most businesses notice nothing except better call quality.
Ongoing support
UK-based support around the clock, plus quarterly reviews to tune call flows as your business grows.
Industries we help
Built for way your sector works
From single-site businesses to multi-location teams, Calilio adapts to each sector’s customer communication and call-management needs.
Real Estate
Route property enquiries to available agents and keep business calls connected across offices, sites, and mobile teams.
Learn MoreRetail & E-commerce
Keep every store reachable, route calls by location, and stop tying sales lines to a copper cabinet in the stockroom.
Learn MoreEducation
Safeguarding-friendly call recording, parent communication lines and reliable emergency calling across every building.
Learn MoreHotels & Hospitality
Front-desk, reservations and guest services on one system, with numbers that follow staff around the property.
Learn MoreConstruction
Site offices open and close; your numbers shouldn't. Softphones give every site the head-office number from day one.
Learn MoreManufacturing
Connect the plant floor, the office and suppliers without relying on ISDN circuits due for the skip.
Learn MoreRecruitment & Staffing Agencies
Organise candidate and client calls across recruiters, branches, departments, and remote teams from one cloud phone system.
Learn MoreLogistics & Multi-site
One dashboard for every depot and driver. Add a new location in minutes, not engineering visits.
Learn MoreProof, not promises
Businesses that switched early: why they're glad they did
“With the PSTN switch-off approaching, we wanted a phone system that wasn’t tied to one office or personal mobile.Calilio gave us a professional UK number, and access from both laptops and mobiles.We now miss fewer enquiries, follow up faster and have clear records of every client call.Since switching, missed calls have dropped by 67%, response times are under 45 minutes, and we save around six hours each week.”
“Preparing for the move away from traditional phone services made us realise how dependent customer calls were on one mobile device. With Calilio, four team members can answer the same UK business number, separate customer and wholesale enquiries, and see which callbacks still need attention. Our missed-call rate has since fallen from 22% to 10%.”
“The PSTN switch-off prompted us to review whether our business calling setup was ready for the future. We ported our existing number to Calilio and gave sales, onboarding and support access to one shared cloud phone system. Calls now reach the right team, customer context stays visible, and our median response time has fallen from over three hours to 51 minutes”
FAQs
PSTN switch off questions, answered
179 days until copper network goes silent
Switch before switch off.
Keep every call, every number, every customer.
30-minute demo shows exactly how your numbers, call flows and teams move to Calilio, with migration plan tailored to your business, free.