PSTN Migration
The national PSTN and ISDN networks are being decommissioned, requiring every organisation to transition to digital services before the final cut-off. For multisite estates, branch networks, retail stores, remote offices, warehouses, service sites and critical environments, this shift impacts far more than just phone lines.
Our PSTN Migration service provides a structured, secure and low-risk transition to modern, IP-based voice and data across your entire estate, ensuring continuity, compliance and stronger communications for the future.
The national PSTN and ISDN networks are being decommissioned, requiring every organisation to transition to digital services before the final cut-off. For multisite estates, branch networks, retail stores, remote offices, warehouses, service sites and critical environments, this shift impacts far more than just phone lines.
Our PSTN Migration service provides a structured, secure and low-risk transition to modern, IP-based voice and data across your entire estate, ensuring continuity, compliance and stronger communications for the future.
Modern, Reliable Connectivity For a Digital First Organisation
Future-ready communications across your estate
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Enables cloud telephony, hybrid work and modern collaboration tools
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Scalable architecture ready for new sites, devices and services
Stronger continuity and resilience
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Built-in failover to keep voice services running during outages
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Centralised control to reroute calls and maintain availability
Reduced operational costs
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Remove legacy PSTN lines and simplify billing across sites
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Lower maintenance overheads with modern, digital voice services
What’s Being Switched Off
The PSTN switch-off impacts all legacy, copper-based voice and data services:
PSTN and ISDN lines (ISDN2 and ISDN30)
Analogue building and safety systems such as alarms, lift lines, and door entry
Operational devices including PDQs and payment terminals
Telemetry, monitoring and IoT equipment running on analogue circuits
PSTN Switch-Off Guide
Preparing You For
The PSTN Switch Off
Identify
Clarity on every service, device and system that relies on PSTN
Helping you understand which of your current lines, devices and services rely on PSTN or ISDN – from voice to alarms, lift lines, payment terminals and IoT systems.
You’ll have a complete and accurate view of what must be migrated before the switch‑off.
Evaluate
Insight into operational impact and what must change before the switch‑off
We assess the impact of the switch‑off across your estate, highlighting risks, priorities and any locations that require early action.
This ensures you’re fully prepared for the transition and aligned with the PSTN switch‑off timeline.
Plan
Low‑risk migration routes tailored to every site and service
We create clear, low‑risk migration pathways for every affected site and service, tailored to your operational needs.
This structured approach simplifies your transition to digital voice and ensures continuity across your organisation.
Our Core Solutions
PSTN Discovery & Migration Management
Managing PSTN migration with a full site audit to minimise disruption.
- Comprehensive mapping of PSTN, ISDN and analogue services
- Identification of critical dependencies (alarms, lifts, payment terminals)
- Clear recommendations for migration pathways and phased implementation with controlled cutover
Digital Voice & SIP Migration
Transitioning your telephony estate to modern SIP or cloud‑based voice services.
- SIP trunking and IP voice deployment
- Number porting, service consolidation and routing design
- Support for hybrid and on‑premise telephony environments
Communications Modernisation for Multisite Estates
Unifying voice services across distributed locations for scalability.
- Standardised voice architecture across all sites
- Centralised policy, routing and call management
- Rapid rollout for retail, offices, warehouses and critical services
Data & Infrastructure Readiness
Preparing environments for IP voice and device compatibility.
- Router, switch and connectivity readiness checks
- Compatibility testing for alarms, safety systems and analogue devices
- 4G/5G failover options for critical voice continuity
Migration Journey
Discovery & Audit
Identify PSTN-dependant lines and devices
Highlight risks and priority sites
Provide full estate visibility
Design & Network Readiness
Create a tailored migration plan
Validate network readiness for IP voice
Define clear migration timelines
Migrate
Phase migration across sites
Move voice, alarms and PDQ's to IP
Minimise disruption during cutover
Validate
Test and verify digital voice services
Confirm site reliability post-migration
Optimise performance
Support
Ongoing monitoring and management
Update configurations as estates evolve
Maintain long-term voice resilience
Why VCG for PSTN Migration?
Specialists in large, distributed estates
End-to-end delivery without reliance on multiple partners
Deep network & voice expertise
Structured, low-risk migration framework
24/7 monitoring and operational
We do more than connectivity!
Ready to Transform
Your Network?
Talk to our experts to understand how we can support your organisations move to secure, modern and resilient digital voice
