The UK's ISDN and PSTN network is being switched off, and any business still relying on ISDN or analogue lines will need to move before it happens. Here's what's changing, when, and what your options are.
What’s Happening and When
- September 2023 — Openreach’s “Stop Sell” came into effect, so new ISDN and PSTN lines can no longer be ordered anywhere in the UK.
- 31 January 2027 — the confirmed date for full ISDN and PSTN withdrawal. After this point the old network is switched off.
Does It Affect Your Business?
It does if you have ISDN lines (often ISDN2 or ISDN30) feeding an on-site phone system, or traditional analogue phone lines. Lines built on Wholesale Line Rental (WLR) are affected too, even if you don't think of them as “ISDN”. Alarms, door entry systems and card machines that use a phone line can also be affected, so they are worth checking.
What Replaces ISDN?
There isn't a single like-for-like replacement. The right option depends on what your business already has:
- SIP trunks — the closest direct replacement. They connect your existing phone system to the phone network over an internet connection, so if you are happy with your phone system you can often keep it. See our business SIP trunks page.
- A hosted phone system — a full move to the cloud, with no on-site phone system to maintain. This suits businesses with ageing hardware or staff who work away from the office. See our business phone systems page.
What to Do Now
- List what runs on your phone lines — phones, fax or alarm lines, lifts, door entry and card machines.
- Check your internet connection — voice over IP needs a stable connection, and a backup is sensible. See business internet failover.
- Confirm number porting — you can almost always keep your existing numbers, but this needs arranging in advance.
- Don’t leave it late — this is a hard cut-over, not a gradual change, and installers get busy as the deadline approaches.
Get connected with an accredited Plustel partner to plan your move away from ISDN.
Get a Quote
How Plustel Fits In
Plustel provides both routes: SIP connectivity as a direct replacement for ISDN circuits, and our hosted platform, Cloud X. As with all our services, we work entirely through accredited partners rather than selling directly, so you'll be connected with a partner who can review your lines and plan the migration.
For the full timeline and more detail, read our ISDN and PSTN switch-off guide. Otherwise, get in touch below and we'll connect you with a partner.