Key Takeaways
- Every ISDN30 and ISDN2e line in Belfast and Northern Ireland will be permanently switched off in January 2027
- Thousands of NI businesses — from Belfast city centre to Lisburn, Bangor, Newry, and Derry — are still running on ISDN
- You can keep your existing Avaya or Panasonic phone system by migrating to SIP trunking
- Alternatively, replace everything with hosted VoIP for a fully managed cloud phone system
- Drakos Systems is Belfast-based and specialises in ISDN migration across Northern Ireland — free migration audit available
The ISDN Switch Off Is Hitting Northern Ireland Hard
In January 2027, BT Openreach will permanently decommission the entire ISDN and analogue telephone network across the United Kingdom. For businesses in Belfast and Northern Ireland, this is not a distant concern — it is an urgent deadline that is now less than a year away.
Northern Ireland has a higher proportion of businesses still relying on traditional ISDN lines compared to many parts of the UK. The reasons are straightforward: NI has a strong base of established SMEs that invested in reliable Avaya and Panasonic phone systems years ago, and those systems have been running perfectly on ISDN ever since. There has been no compelling reason to change — until now.
The ISDN switch off does not discriminate by location or business size. Whether you are a solicitor's office in Belfast city centre, a hotel in Bangor, a manufacturing firm in Lisburn, a medical practice in Newtownards, or a logistics company in Newry — if you have ISDN lines, they will stop working in January 2027. No exceptions, no extensions, no workarounds.
Which NI Businesses Are Affected?
The scale of the impact across Northern Ireland is significant. Businesses in every sector and every area are affected:
Belfast City Centre and Greater Belfast
Belfast has the highest concentration of ISDN-connected businesses in Northern Ireland. Professional services firms, legal practices, financial services companies, call centres, and corporate offices throughout the city centre, Titanic Quarter, and surrounding business parks are running on ISDN30 PRI circuits. Many of these businesses have Avaya IP Office systems that have served them reliably for 10-15 years. The ISDN cards inside those Avaya systems will have nothing to connect to after January 2027.
Lisburn and Castlereagh
Lisburn's growing business community includes retail operations, distribution centres, and professional services — many connected via ISDN2e BRI lines to smaller Panasonic PBX systems. The Sprucefield and Derriaghy industrial areas have numerous businesses that need to migrate before the deadline.
Bangor and North Down
Hotels, guest houses, and hospitality businesses along the North Down coast frequently use Panasonic systems with DECT cordless handsets connected via ISDN. Medical practices and dental surgeries in the area also rely heavily on ISDN2e lines for their phone systems and fax machines.
Newry, Craigavon, and the South
Cross-border businesses in Newry, manufacturing firms in Craigavon, and agricultural suppliers throughout County Armagh and County Down are affected. Many of these businesses have analogue lines for alarm systems, card payment terminals, and fax machines in addition to their main ISDN phone system.
Derry, Omagh, and the West
Businesses across the west of Northern Ireland — from Derry's city centre offices to rural enterprises in Tyrone and Fermanagh — face the same deadline. Distance from Belfast does not change the timeline, but it does make it even more important to work with a provider that has local engineers who can attend your premises.
What Exactly Is Being Switched Off?
Every type of traditional phone line in Northern Ireland is being decommissioned. This includes:
- ISDN30 (PRI) — 30-channel circuits used by medium and large businesses. Connected to PBX systems via PRI trunk cards. Common in Avaya IP Office and larger Panasonic installations
- ISDN2e (BRI) — 2-channel circuits used by smaller businesses. Connected to PBX systems via BRI cards. Very common in smaller Panasonic NS700 and older TDA systems across NI
- Analogue lines (PSTN) — Single-channel lines used for individual phones, fax machines, alarm systems, lift phones, door entry systems, and card payment terminals
For a comprehensive breakdown of each line type and what happens to connected devices, read our complete ISDN Switch Off 2027 guide.
⚠️ Important: BT Openreach stopped selling new ISDN lines in September 2023. No new ISDN installations are possible anywhere in Northern Ireland. The network is being permanently decommissioned.
Your Two Migration Options
Every NI business affected by the ISDN switch off has two clear paths forward. The right choice depends on your current system, your budget, and your plans for the next 3-5 years.
Option A: SIP Trunking — Keep Your Existing Phone System
SIP trunking replaces your ISDN lines with internet-based voice connections while keeping your existing PBX system in place. Your Avaya or Panasonic system stays exactly where it is — only the lines coming into it change.
- Avaya IP Office — We remove the ISDN30 PRI card and configure SIP trunks via Avaya Manager. Your handsets, extension numbers, hunt groups, voicemail, and all programmed features continue working unchanged
- Panasonic NS700/NSX — We remove the ISDN cards and configure SIP trunks via the Panasonic web interface. All digital phones, DECT cordless handsets, and call routing remain the same
- Cost saving — SIP trunks cost £3-8 per channel per month compared to £15-25 for ISDN. Most businesses save 50-70% on line rental immediately
- Speed — A straightforward SIP migration can be completed in a single day for most systems
- Number porting — All your existing Belfast 028 numbers are ported to the SIP trunk. Your customers notice nothing
SIP trunking is the fastest, lowest-cost migration path. It is ideal if your Avaya or Panasonic system is working well and you want to extend its life while eliminating ISDN costs. Learn more about the full migration process in our PBX to VoIP migration guide.
Option B: Hosted VoIP — Replace Everything with Cloud
Hosted VoIP removes your PBX entirely and moves your phone system to the cloud. No on-premise hardware to maintain — everything is managed by Drakos Systems.
- Modern features — Mobile apps, call recording, Microsoft Teams integration, CRM connectivity, video conferencing, and AI-powered call transcription
- Work from anywhere — Your team can take calls from the office, from home, or from their mobile phone with the same business number
- No maintenance — No PBX hardware to repair, no annual maintenance contracts, no engineer visits for software updates
- Scalable — Add or remove users as your business grows. No need to buy additional PBX cards or licenses
- Monthly subscription — £8-15 per user per month with all features included
Hosted VoIP is the right choice if your current system is aging, if you want modern features, or if you want to eliminate all on-premise telephony hardware. Visit our business phones service page for full details on our hosted VoIP platform.
Avaya Migration for Belfast and NI Businesses
Avaya IP Office is one of the most widely deployed phone systems in Northern Ireland. Thousands of NI businesses — from 10-user offices to 200+ seat contact centres — rely on Avaya IP Office 500 V2 systems connected via ISDN30 PRI.
The good news: Avaya IP Office supports SIP trunking natively from software release R9.1 onwards. In most cases, we can migrate your Avaya system from ISDN to SIP in a single day with zero disruption to your business. Your handsets, extension numbers, hunt groups, voicemail greetings, auto-attendant menus, and every programmed feature transfer directly.
If your Avaya system is reaching end of life or you want access to modern features like mobile apps and call recording, we can also replace it entirely with our hosted VoIP platform. Read our dedicated Avaya replacement guide for Northern Ireland for a detailed comparison of your options.
Panasonic Migration for Belfast and NI Businesses
Panasonic PBX systems are particularly widespread across Northern Ireland — especially in hospitality, retail, medical practices, and small offices. The Panasonic NS700, NSX, and older TDA series are found in businesses throughout Belfast, Lisburn, Bangor, and across the province.
Panasonic NS700 and NSX systems support SIP trunking, making migration straightforward. We remove the ISDN trunk cards, configure SIP trunks via the web interface, and your system continues operating as normal. All Panasonic digital phones and DECT cordless handsets keep working without any changes.
For older Panasonic TDA systems that may not support SIP trunking, or for businesses wanting to modernise, we offer a full replacement with hosted VoIP. See our Panasonic PBX replacement guide for detailed options.
Do Not Forget Your Analogue Lines
Many NI businesses focus on their main phone system and forget about the analogue lines running quietly in the background. Every analogue line must be identified and migrated before January 2027:
- Fax machines — Replace with email-to-fax or fax-over-IP service
- Alarm systems — Upgrade to IP or 4G alarm communicator
- Lift emergency phones — Replace with 4G GSM gateway or IP lift phone
- Door entry systems — Upgrade to SIP-compatible door panels
- Card payment terminals — Request a 4G or broadband terminal from your payment provider
Alarm systems and lift phones have safety and legal implications — these must be migrated with time to spare for thorough testing.
Why NI Businesses Choose Drakos Systems
- Belfast-based team — Our engineers are based in Belfast with on-site support available across all of Northern Ireland. We are not a remote-only provider
- Avaya and Panasonic specialists — We have migrated hundreds of Avaya and Panasonic systems from ISDN to SIP across NI. We know these systems inside and out
- End-to-end service — Audit, broadband assessment, SIP provisioning, number porting, configuration, testing, go-live support, and ongoing management
- ISO 27001 certified — Our information security management is independently audited and certified
- Honest advice — If SIP trunking is the right choice for your business, we will tell you. If hosted VoIP makes more sense, we will tell you that too. No pressure, no upselling
- Local knowledge — We understand the NI business landscape, the broadband infrastructure across different areas, and the specific challenges that Northern Ireland businesses face
Frequently Asked Questions
When will ISDN be switched off in Belfast and Northern Ireland?
All ISDN30 and ISDN2e lines across Belfast and Northern Ireland will be permanently switched off in January 2027. This is part of the UK-wide decommissioning of the entire ISDN and analogue telephone network by BT Openreach. There are no regional exceptions or extensions — every ISDN circuit in Northern Ireland will cease to function on the same timeline as the rest of the UK.
How many businesses in Northern Ireland are affected?
Thousands of businesses across Northern Ireland still rely on ISDN lines for their phone systems. Any business using ISDN30 PRI, ISDN2e BRI, or analogue phone lines is affected — this includes offices, hotels, medical practices, retail shops, manufacturing firms, and call centres in Belfast, Lisburn, Bangor, Newry, Derry, Craigavon, and every other area of NI.
Can I keep my Avaya or Panasonic system after the ISDN switch off?
Yes. Both Avaya IP Office and Panasonic NS700/NSX systems support SIP trunking. Drakos Systems can migrate your existing system from ISDN to SIP trunks, keeping your handsets, extension numbers, hunt groups, voicemail, and all programmed features unchanged. Only the lines coming into your system change — everything else stays the same.
Is there a local ISDN migration specialist in Belfast?
Yes. Drakos Systems is based in Belfast and specialises in ISDN to SIP migration for Avaya and Panasonic systems across Northern Ireland. We provide on-site engineering support, free migration audits, and handle the entire process from initial assessment through to go-live and ongoing management. Call us on 02890 184 600.
What happens if my NI business does nothing before the ISDN switch off?
Your phone lines will stop working in January 2027. You will have no incoming or outgoing calls. Any devices connected to analogue lines — fax machines, alarms, lift phones, card terminals — will also stop functioning. There is no grace period, no extension, and no workaround. You will remain without phone service until you complete a migration to SIP trunking or hosted VoIP.
Get Your Free ISDN Migration Audit
The ISDN switch off is less than a year away. Telecoms providers will be overwhelmed in Q4 2026 — NI businesses that leave it late risk being without phone service when the deadline hits.
Contact Drakos Systems today for a free ISDN migration audit. We will assess your current lines, recommend the right migration path for your Belfast or NI business, and give you a clear quote — no obligation, no pressure.
About the Author: Drakos Systems provides business phone solutions including Avaya and Panasonic SIP migration, hosted VoIP, and SIP trunking for businesses across Belfast and Northern Ireland. With 20+ years of experience and ISO 27001 certification, we are the trusted local partner for ISDN migration in NI.