If your business still takes calls on an analogue line or an ISDN system, you're on borrowed time. Openreach is switching off the UK's old PSTN (Public Switched Telephone Network) and ISDN infrastructure, and once your exchange is migrated, those lines simply stop working. For many SME owners this sounds like an IT problem to deal with "later" — but phone lines are often tied to card payment machines, alarm systems, fax machines and the number customers have called for years. Leave it too late and you risk a scramble that disrupts the one thing your business can't afford to lose: the ability to answer the phone.
Why this is happening
Openreach is retiring the copper-based PSTN and ISDN network in favour of all-IP connections, with full withdrawal happening exchange by exchange across the country. It isn't optional and it isn't a sales tactic — the old network is genuinely being decommissioned because it's expensive to maintain and increasingly unreliable. Every business and residential line in the UK will eventually move to a digital, internet-based alternative, most commonly VoIP (Voice over Internet Protocol).
What VoIP actually involves
VoIP replaces physical phone lines with calls carried over your internet connection. Instead of a phone socket wired back to an exchange, your handsets (or softphone apps on a laptop or mobile) connect through your broadband or a dedicated data circuit. In practice, for most SMEs this means:
- A cloud-hosted phone system rather than an on-site PBX box
- IP handsets, or software you can run on existing devices
- Your existing phone numbers ported across so customers notice nothing
- Features like call routing, voicemail-to-email and mobile apps that old ISDN systems couldn't offer
The key dependency is your internet connection. VoIP call quality is only as good as the connectivity underneath it, which is why it's worth reviewing your broadband or leased line capacity before, not after, you migrate.
What to check with your current provider
Before you do anything, get clear answers from your existing phone and line provider on the following:
- Your switch-off date — ask specifically when your exchange is scheduled to stop ISDN/PSTN service, not just the national deadline
- Contract end dates — check for early termination charges on existing line or system contracts
- Connected equipment — list anything using your current lines: card machines, alarms, lift lines, fax, fire panels, CCTV dialers
- Number porting — confirm your provider (old or new) can port your existing numbers rather than issuing new ones
- Support during transition — ask who is responsible if something breaks during the cutover
Many SME owners are surprised to find equipment they'd forgotten about is still relying on an old analogue line, so this audit step matters more than it seems.
Planning a switchover without disruption
The businesses that struggle with this migration are the ones that leave it until their provider forces a deadline. A controlled switchover looks like this:
- Audit first — map every line, number and connected device before choosing a new system
- Test connectivity — confirm your broadband or leased line has the bandwidth and resilience for voice traffic, including a backup route if your main internet connection drops
- Run both systems in parallel — a short overlap period where old and new systems both work avoids a hard cutover on one date
- Train staff before go-live — new handsets and call-routing rules should be familiar before customers start ringing in
- Keep a fallback plan — mobile call forwarding as a safety net for the first few days catches anything missed
Done properly, customers never notice the change happened at all — calls arrive at the same number, to the same team, without interruption.
Don't wait for the deadline
Exchange migration dates are being brought forward as the national programme accelerates, and VoIP providers, installers and number-porting teams get busier as deadlines approach. Starting the planning now, while you have options and time, puts you in control of the switchover rather than reacting to a provider's notice.
Valetech Solutions helps Greater Manchester SMEs plan and deliver PSTN/ISDN-to-VoIP migrations, from auditing existing lines and equipment through to installing cloud phone systems with the connectivity to back them up. If your business is still on analogue or ISDN lines, now's the time to get a plan in place. Get in touch with Valetech Solutions.