How much does a business phone system cost in Northern Ireland in 2026?

A hosted (cloud) business phone system for a Northern Ireland business typically costs between about £10 and £30 per user per month, before VAT, at the list prices UK providers publish [1][2]. On top of that you may pay for desk phones or headsets, set-up and number porting, and you need a reliable broadband connection. Traditional phone lines and ISDN are being switched off: BT plans to retire the old landline network by 31 January 2027 [3], so most businesses are now choosing between a hosted phone system and Microsoft Teams Phone rather than renewing old lines.

The short version

• Hosted phone systems are priced per user, per month. Published UK list prices run from about £10 to £30, depending on the features and call minutes included.
• The old copper phone network and ISDN close on 31 January 2027. Lines that haven't moved may be put on a basic emergency service or lose service altogether [4][5].
• Check anything else that uses a phone line before you switch: alarms, lift phones, card machines, door entry and fire alarm monitoring [4].
• Digital phones need power and broadband. Plan for power cuts and keep a mobile available for 999 calls.

What does a hosted phone system cost per user?

Hosted phone systems (also called cloud phone systems or hosted VoIP) are billed per user, per month. The price depends mainly on how many call minutes are included and on features such as call queues, call recording and integration with Microsoft Teams or your CRM. Two examples of published UK list prices, read on 2 November 2026:

These are examples to show the range, not a recommendation. Independent UK price guides give a similar picture: basic plans from about £7 to £13 per user per month, mid-range £14 to £20 and premium £20 to £30 [9], with fully managed hosted systems, where the provider sets up and supports everything, at about £15 to £35 [10]. Managed providers often bundle the phone system with handsets, numbers and support, so compare what's included rather than the headline price. We found no Northern Ireland-specific price survey, so these are UK-wide figures.

What else does a business phone system cost?

An on-premise system is a large one-off cost plus maintenance, and it still needs digital lines or a SIP connection once the old network closes. A hosted system swaps that for a monthly per-user fee, with the provider looking after the equipment and updates.

What is a softphone app, and why does it matter?

A softphone is an app that turns a mobile or a computer into a phone on your business system. Staff make and take calls on the office number from the app, with the same transfers and call queues as a desk phone, and their personal mobile number stays private. Most hosted systems and Teams Phone include apps for Windows, Mac, iPhone and Android in the per-user price [11].

For hybrid and mobile staff, that means the office number follows them home, on site and on the road, without diverting calls or paying for a desk phone they rarely use. It also helps in a power cut or broadband outage at the office, because calls can still reach people on their mobiles.

How does a hosted phone system compare with traditional line rental?

What is the PSTN and ISDN switch-off, and when does it happen?

The PSTN (public switched telephone network) is the old copper landline network. Ofcom says "BT plans to retire its old landline network by 31 January 2027", and that customers on the BT Openreach network should be moved to a digital landline, or a service that works like one, by then [3]. Openreach, which runs the network in Northern Ireland as in the rest of the UK, says that on 31 January 2027 "all traditional phone lines will need to move to a digital service" [4]. BT lists ISDN among the networks being switched off and says ISDN services "cannot be moved automatically": unless they are moved to an IP-based service, they "will stop working from 31 January 2027" [5].

Many businesses still haven't moved. At the end of July 2026, Openreach estimated that around 1.5 million lines were still on the old copper network, including around 350,000 business premises [6]. If you don't move in time, Openreach warns you "may be moved onto an emergency voice-only access service (EVAc)" or "may lose your service altogether" [4].

What else uses your phone line?

This is where switchovers go wrong. Openreach tells businesses to check all equipment, services and wiring connected to the phone line, naming [4]:

• Intruder alarm systems and fire alarm monitoring
• CCTV
• Card payment terminals
• Door entry systems
• Lift emergency phones

Ask each equipment supplier whether it works on a digital line, or whether it needs a new unit or a mobile (SIM-based) connection. Also tell your provider about any care alarm or telecare device, because Ofcom warns they might not work properly on a digital landline [3].

Can you keep your phone numbers?

Yes. Ofcom confirms you can keep your number when your landline goes digital [3], and when you move to a new provider your numbers can be transferred (ported) to them. The new provider normally arranges the port. Before you switch, list every number you own, including any you only use for fax or direct dials, so nothing is left behind on the old lines.

What broadband do you need, and what happens in a power cut?

Voice calls use very little bandwidth. Microsoft, for example, recommends 58 kbps each way for a Teams audio call [7], so 15 people on calls at once need under 1 Mbps. What matters more is a stable connection: business-grade broadband, a router that prioritises voice traffic, good Wi-Fi if people use softphones, and ideally a backup connection such as 4G that takes over if the main line fails.

Digital phones need mains power. Ofcom notes digital landlines "will not work in a power cut unless there is a battery back-up", and providers must offer a free back-up lasting at least an hour to customers who depend on their landline [3]. For a business, the practical answer is to divert calls to mobiles when the office is down, keep at least one charged mobile for 999 calls, and make sure each number's registered address is correct, especially for staff who work from home.

What would a 15-person office pay?

Take a 15-person office in Lisburn with a main number, a sales queue, an alarm and a card machine on the old lines:

At list prices, the phone system alone for 15 people comes to roughly £1,800–£5,400 a year before VAT, plus handsets and set-up. Using the middle of each range, a typical budget is around £300 a month for the system, with handsets and set-up as a one-off cost.

Should you choose Teams Phone or a hosted phone system?

If your team already lives in Microsoft Teams, Teams Phone lets them make and take ordinary phone calls in Teams on their laptop, mobile or a certified desk phone. It needs a Teams Phone licence for each user plus a connection to the phone network, through a Microsoft Calling Plan, an operator via Operator Connect, Teams Phone Mobile or Direct Routing [8]. Microsoft's UK list prices, ex VAT on an annual commitment and checked 3 November 2026, are £7.70 per user per month for Teams Phone Standard on its own, £9.20 for Teams Phone with pay-as-you-go calling, £13.10 for Teams Phone with a domestic Calling Plan (a UK number and 3,000 outbound UK minutes) and £26.10 with domestic and international calling [12]. Each user also needs a Microsoft 365 or Teams licence that includes Teams [12].

Teams Phone tends to fit offices that already work in Teams all day, where most calls are made from laptops and call handling is simple: a main number, an auto attendant and a few queues. A hosted phone system tends to fit when reception or sales handle a lot of calls on desk phones, when you need call recording, wallboards and reporting, or when some staff don't use Teams. Many hosted systems integrate with Teams, so it isn't always one or the other. Compare the full per-user cost: Teams Phone with a Calling Plan, at £13.10, sits within the range of many hosted plans [1][2][12].

What does BTNI supply?

With TechState™, a managed phone system is included in the package, with softphone apps for mobile and PC and one handset or headset per user; our Communications service sets out what's covered. BTNI also supplies phone systems on their own, separately from TechState™ packages. For a free quotation, email [email protected] or call 028 9244 3424.