Business phone systems
On-premise or hosted systems still anchored to PSTN, ISDN or WLR lines need a clear migration path.
UK connectivity & voice
The PSTN & ISDN switch-off is coming. Is your business ready?
Traditional UK phone lines are being retired by January 2027. If your business still relies on old phone lines for calls, alarms, card machines, broadband, lifts or door entry systems, now is the time to review your setup.
- Review old phone lines, ISDN and analogue services
- Plan your move to VoIP, fibre and resilient connectivity
- Avoid last-minute disruption before the 2027 deadline
What is the PSTN & ISDN switch-off?
The UK is moving away from traditional copper-based phone services towards modern digital services that run over internet connectivity. This means older PSTN, ISDN and WLR-based services are being withdrawn and businesses need to move to suitable alternatives.
The change is network-wide and planned in phases. For most organisations the practical focus is understanding what still depends on those older services, then lining up voice, connectivity and third-party systems so everything continues to work smoothly.
Key date
31 January 2027
Traditional PSTN/WLR-based services are expected to be retired by this date.
It is not just your office phones
Many businesses have more than just calls running over older phone lines. A readiness check helps identify hidden services before they become a problem.
Analogue phone lines
Single-line and multi-line analogue services used for voice or data will not continue in their current form.
ISDN lines
ISDN2 and ISDN30 circuits underpin many older voice platforms and need digital or IP-based replacements.
Fax machines
Devices that rely on an analogue line often need an alternative such as secure digital fax or workflow tools.
Alarm lines
Intruder and fire signalling paths may still use PSTN; your monitoring provider can confirm compatibility.
Lift emergency phones
Emergency lift lines are safety-critical and must be checked against approved digital options.
Door entry systems
Intercoms and access panels sometimes use copper phone lines for calls or unlock signalling.
Card machines / EPOS
Some terminals and tills still dial out or backhaul over legacy phone infrastructure.
CCTV or monitoring lines
Remote signalling for cameras or DVRs can still ride on older circuits at some sites.
Broadband linked to legacy phone services
FTTC and some business broadband products use a phone line as part of the access architecture.
Remote monitoring equipment
Equipment in plant rooms, refrigeration or utilities may use PSTN for low-frequency dial-out.
Multi-site connectivity
WANs that depend on legacy tails or diverse routing over WLR-based services should be reviewed end to end.
A simple three-step plan
Step 1
Audit
Identify phone lines, broadband circuits, devices and systems that still rely on legacy services.
Step 2
Plan
Decide the right replacement approach, such as VoIP, FTTP, leased line, mobile backup, SIP trunks or new hardware.
Step 3
Migrate
Move services safely before the deadline, with number porting, testing and support.
Practical support from a connectivity and voice specialist
Clever Connected helps businesses review, replace and manage legacy phone and connectivity services. We do not just sell a phone system: we look at the full setup, including internet resilience, call flows, number porting, routers, backup connectivity and business continuity.
How we can help
- PSTN & ISDN readiness checks
- VoIP phone systems
- Number porting and call flow planning
- FTTP, FTTx and leased line connectivity
- 4G/5G backup and failover
- Managed routers and network edge
- Multi-site connectivity planning
- Ongoing support and supplier management
Why choose Clever Connected?
- Technical, infrastructure-first advice
- Clear recommendations without jargon
- Business-grade connectivity and voice solutions
- Designed around uptime and resilience
- Suitable for SMEs, professional services, hospitality and multi-site businesses
Ideal for businesses that rely on staying connected
If continuity matters to you, a structured review now saves complexity later.
Offices and professional services
Teams that depend on reliable calls, client contact and cloud tools day to day.
Hotels, hospitality and venues
Sites with guest phones, door entry, lifts and card payments across busy public areas.
Retail and EPOS-heavy businesses
Shops and chains where tills, PDQs and back-office lines still touch legacy networks.
Healthcare, clinics and care providers
Organisations where continuity, alarms and communications must stay dependable.
Multi-site businesses
Groups that need consistent voice, connectivity and supplier coordination across locations.
Businesses moving premises
Moves are a practical moment to retire legacy services and align fibre, voice and resilience.
Book your free PSTN & ISDN readiness check
Tell us a little about your current setup and we will help you understand what may be affected and what your options are.
Do not wait until the deadline is close
The earlier you review your setup, the easier it is to plan a clean migration, avoid rushed decisions and make sure the right connectivity is in place before legacy services are withdrawn.
Book a free readiness check