We’re here to help you
The UK’s PSTN/ISDN networks are being withdrawn. Analogue voice, ISDN2/ISDN30 and many copper‑based broadband and device lines will cease. We help businesses, charities and multi‑site organisations audit, plan and migrate to All‑IP alternatives with resilience built‑in.
What Is PSTN Replacement?
PSTN replacement is the process of moving services away from the UK’s old copper phone network (PSTN and ISDN) to modern digital, All‑IP alternatives. BT are planning for the legacy network to be fully switched off by 31 January 2027, meaning any service that relies on analogue lines — including phone lines, ISDN, ADSL/FTTC broadband, lift lines, alarms and other connected devices — must migrate to digital replacements such as VoIP, SIP, FTTP/SoGEA, 4G/5G, and IP‑based signalling.
PSTN replacement ensures continued operation, improved reliability, modern features, and long‑term support as the UK moves to a full fibre and All‑IP future.
Many services still depend on PSTN/analogue lines:
Communications
Connectivity
Critical & Safety Systems
If these are not migrated, they will simply stop working after switch‑off, creating operational and safety risks.
1) Audit & Discovery
We catalogue every PSTN‑dependent device (including “hidden” lines in lifts, panels, gates, comms rooms).
Deliverable: Line & Device Inventory + Risk Map
2) Design & Options
Per‑service replacement design (voice, broadband, critical systems).
Deliverable: Migration Design (SIP/Hosted, FTTP/SoGEA/Ethernet, LTE backup, UPS plan)
3) Pilot & Prove
Prove signalling and resilience (power failure, ISP failure, SIM failover).
Deliverable: Pilot Sign‑off & acceptance results
4) Rollout & Numbering
Coordinated installs, number porting, gateway deployment, documentation.
Deliverable: Site‑by‑Site Migration Plan and change window
5) Monitoring & Support
24/7 monitoring options for critical paths; UK support for incidents, updates and changes.
Deliverable: Ongoing Reporting & Support SLAs
| Existing PSTN/ISDN Service | Recommended Replacement |
|---|---|
| PSTN voice line | Hosted VoIP / Teams Phone / Digital single‑line |
| ISDN2e / ISDN30 | SIP Trunks (or migrate to Hosted/Teams) |
| ADSL / FTTC | FTTP or SoGEA (5G/dual‑path failover optional) |
| Lift emergency phone | ATA/ISDN‑TA + LTE backup + UPS + monitoring |
| Fire / intruder / telecare alarms | IP alarm signalling via ATA/gateway + 4G failover |
| Door entry / intercom | IP intercom or ATA + resilient router |
| PDQ / legacy fax | IP‑enabled terminals or inbound fax‑to‑email |
| SOS/help points, barriers & gates | Rugged router + monitored 4G/5G or dual‑path WAN |
Many connected building systems still rely on analogue lines. We provide digital alternatives using ruggedised routers, ATAs, SIP gateways and monitored LTE/5G connections.
Lift emergency phones rely on analogue PSTN lines that are being withdrawn. We provide fully managed digital replacement solutions using resilient 4G/VoLTE connectivity, battery-backed gateways and analogue adaptation for existing autodiallers.
Our solution includes
A reliable business internet connection is essential. Spectrum can assess your current connectivity and recommend improvements such as FTTP, Ethernet or leased lines if needed.
Speak to a Specialist on 01283 749 990 or drop your details into our contact form – we’re happy to help.
Spectrum was created with the aim of providing clients with cost effective solutions for communication services, supported by exceptional account management.
Spectrum’s highly skilled and experienced team is focused on keeping at the forefront of telecoms technology including product differentiation and market leadership.
