Planning your Avaya, Panasonic or NEC phone system migration before January 2027. SIP trunk migration or full cloud VoIP replacement. Northern Ireland support across Northern Ireland.
If your business phone system was installed more than five years ago and connects to the outside world using ISDN lines, you may now be facing two problems at the same time. Traditional phone lines are being phased out, and many older PBX systems are becoming harder to support. You do not need to panic, but you do need a clear plan.
BT Openreach is switching off the UK's PSTN and ISDN network in January 2027. After this date, any phone system that relies on ISDN lines will not be able to make or receive calls via those lines. Businesses need to act before this deadline.
Calls, apps and routing connected
Replace the ISDN lines with SIP trunks while keeping the existing PBX in place. Works on systems that support SIP and are in good condition. Lower initial cost, but ongoing hardware maintenance responsibility remains.
When this makes sense: your PBX is relatively recent, in good working order, supports SIP natively or via a gateway card, and your handsets are mostly compatible.
Replace the PBX entirely with a hosted cloud phone system. Simpler to manage, no on-site hardware maintenance, works anywhere with an internet connection, and scales easily.
When this makes sense: your PBX is old or unreliable, handsets are proprietary and cannot be reused, you want to add remote worker support, or you want a simpler ongoing management model.
The Avaya IP Office 500 V2 is a common system across Northern Ireland businesses. Many were installed 10 to 15 years ago and have served well. However, several considerations arise around the ISDN switch-off:
Full details on Avaya migration options are in our Avaya replacement guide for Northern Ireland.
Panasonic systems are common in professional offices, medical premises and hospitality across Northern Ireland. Key migration considerations:
Full details on Panasonic migration options are in our Panasonic replacement guide for Northern Ireland.
NEC systems are another common platform across Northern Ireland businesses and public sector organisations. See our NEC phone system replacement guide for detailed information on SL1100, SL2100, SV8100 and SV9100 migration planning.
Ring us and tell us what system you have and when your ISDN contract is due for renewal. We will advise on options, timelines and costs without any obligation.
We have worked with ageing Avaya, Panasonic, NEC and Nortel systems connected to ISDN and PSTN services. The first job is not removing the old system. It is documenting the numbers, extensions, hunt groups, emergency routes, analogue devices, cabling and operational habits that the business still relies on.
Some businesses can retain a suitable PBX and move the external lines to SIP. Others are better served by a hosted or hybrid replacement. Gate openers, intercoms and certain internal phones may continue through an ATA or gateway, subject to compatibility, resilience and any safety requirements.
Large factories and warehouses often have many internal-only or non-essential phones. Charging a full hosted-user licence for every wall phone can make a cloud proposal unnecessarily expensive. Where the platform supports it, we design internal extensions, shared devices, paging or emergency auto-dial phones separately from full office users. SOS buttons, designated-number dialling and fall-detection integrations can also be considered where the approved equipment supports them.
Technical review: Prepared and reviewed by Kieran Bourquin, Drakos Systems. Last reviewed .
BT Openreach is switching off the UK's PSTN and ISDN network in January 2027. After this date, any phone system that relies on ISDN lines will not be able to make or receive calls via those lines. Businesses need to either migrate to SIP trunks or replace the system with a cloud VoIP solution before that date.
It depends on the handset model. Some handsets support SIP and can potentially be reused. Proprietary digital handsets (Avaya 1400/9500 series, Panasonic KX-DT series) cannot be reused on a different manufacturer's platform. We check which handsets you have and advise on reuse or replacement as part of the assessment.
SIP trunking replaces the ISDN lines while keeping the existing PBX in place. Full cloud VoIP replaces the PBX entirely with a hosted platform. SIP migration is lower cost if the PBX is in good condition and supports SIP. Full replacement is simpler to manage long term and avoids ongoing hardware maintenance.
Serving Belfast, Lisburn and Northern Ireland. Direct contact. Onsite support across NI.