If your office phone system still relies on ageing copper lines or clunky on-premise hardware, 2026 is the year to act. With the UK PSTN switch-off now well underway and BT Openreach phasing out traditional landlines by January 2027, every business needs a clear migration plan. The good news? Modern office phone systems are faster to deploy, cheaper to run and packed with features that legacy setups simply cannot match — from instant video conferencing to AI-powered call routing.
This guide breaks down every type of office phone system available to UK businesses in 2026, compares real-world costs, and gives you a practical framework for choosing the right solution — whether you’re a five-person startup or a 500-seat enterprise.
What Is an Office Phone System?
An office phone system is the infrastructure that handles inbound and outbound calls across your organisation. It connects desk phones, softphones, mobile devices and reception consoles into a single managed network — giving staff direct dial numbers, call transfers, voicemail and a range of productivity features.
In 2026, UK businesses broadly choose between four categories:
Traditional PSTN / PBX
The legacy approach. A Private Branch Exchange (PBX) box sits on your premises and connects to the public telephone network via analogue or ISDN lines. Once the standard for every office, these systems are rapidly being retired as the UK’s copper network shuts down. If you’re still on PSTN, you’ll need to migrate before the 2027 deadline — our VoIP vs landline comparison explains why most businesses are choosing internet-based alternatives.
VoIP (Voice over Internet Protocol)
VoIP converts voice into data packets and transmits calls over your broadband connection. It can run on physical IP handsets, desktop softphones or mobile apps. VoIP is the foundational technology behind virtually every modern office phone system — and it’s what makes cloud and hosted solutions possible. For a deeper look, see our guide to hosted VoIP for business.
Cloud-Hosted Phone Systems
A cloud phone system (sometimes called UCaaS — Unified Communications as a Service) is fully managed by your provider. There’s no hardware on-site beyond the handsets themselves; all call routing, voicemail, auto-attendant and analytics run in the provider’s data centres. You pay a predictable per-user monthly fee and can scale up or down instantly. This is the fastest-growing category in the UK — read our dedicated cloud phone system guide for a full breakdown.
Hybrid Systems
Hybrid setups combine on-premise PBX hardware with cloud connectivity. They’re popular with larger organisations that have already invested heavily in physical infrastructure but want to layer on modern features like remote extensions, mobile apps and CRM integration without ripping everything out. Hybrid is a pragmatic middle ground — though it does carry the maintenance burden of on-site equipment.
Types of Office Phone Systems Compared
Choosing between system types is the single most important decision you’ll make. The table below compares all four options across the metrics that matter most to UK businesses in 2026.
| Type | Monthly Cost (per user) | Setup Cost | Best For | Key Features |
|---|---|---|---|---|
| Traditional PBX | £15 – £25 | £2,000 – £10,000+ | Businesses with existing PBX hardware nearing end-of-life | Desk phones, basic call routing, voicemail, conference calling |
| Hosted VoIP | £8 – £18 | £0 – £500 | SMEs wanting low-cost, rapid deployment | Softphones, mobile app, call recording, auto-attendant, voicemail-to-email |
| Cloud Phone System | £10 – £25 | £0 – £300 | Growing businesses, multi-site teams, remote-first companies | UCaaS platform, video conferencing, CRM integration, analytics dashboard, AI features |
| Hybrid | £12 – £22 | £1,000 – £5,000 | Larger orgs with legacy PBX investment wanting a phased migration | On-premise control, cloud bolt-ons, remote extensions, SIP trunking |
Traditional PBX — Pros and Cons
Pros: Full on-site control; no reliance on internet quality; familiar handset experience.
Cons: High upfront cost; expensive maintenance contracts; no native mobile or remote support; approaching end-of-life with the PSTN switch-off. For most businesses, the economics no longer stack up — especially when modern alternatives offer more for less.
Hosted VoIP — Pros and Cons
Pros: Lowest entry cost; quick setup (often same-day); easy to scale; rich feature set even on entry plans; works anywhere with broadband.
Cons: Dependent on internet quality; call quality can suffer on poor connections; limited customisation compared with on-premise. Check our small business phone system guide to see why hosted VoIP is the go-to choice for lean teams.
Cloud Phone System — Pros and Cons
Pros: Full unified communications (voice, video, messaging); enterprise-grade uptime SLAs; deep integrations with CRMs, Microsoft Teams and Google Workspace; advanced analytics and AI call transcription.
Cons: Monthly cost per user can climb with premium add-ons; some platforms lock you into long contracts. That said, the total cost of ownership is typically 40–60% lower than maintaining on-premise hardware over five years.
Hybrid — Pros and Cons
Pros: Protects existing hardware investment; phased migration path; on-premise call processing for latency-sensitive environments.
Cons: More complex to manage; requires in-house or contracted IT support; you still carry hardware maintenance costs alongside cloud subscription fees.
Ready to upgrade your office phones?
Get a free, no-obligation quote for a modern cloud phone system tailored to your business.
How Much Do Office Phone Systems Cost in 2026?
Cost is rarely a single number. To budget accurately, you need to account for three layers of expenditure:
1. Setup and Installation
Cloud and hosted VoIP systems have near-zero setup costs — most providers ship pre-configured handsets and activate your account remotely. Traditional PBX and hybrid installations involve cabling, server hardware and on-site engineering. Expect to pay:
- Cloud / Hosted VoIP: £0 – £500 (handset purchase or rental, network assessment)
- Hybrid: £1,000 – £5,000 (gateway hardware, SIP trunk configuration, integration work)
- On-premise PBX: £2,000 – £10,000+ (server, licensing, cabling, installation labour)
2. Monthly Per-User Fees
Most modern systems charge per user per month. In the UK market in 2026, typical ranges are:
- Basic VoIP seat: £8 – £12/month (calls, voicemail, softphone)
- Standard cloud UCaaS seat: £14 – £20/month (adds video, integrations, analytics)
- Premium seat: £20 – £30/month (AI transcription, call centre features, advanced reporting)
A 20-user business on a standard cloud plan would therefore spend roughly £280 – £400 per month — significantly less than maintaining an on-premise PBX with support contracts, line rental and ISDN charges.
3. Additional Costs to Watch
- Number porting: Usually free, but some providers charge £5 – £10 per number
- International call bundles: £2 – £8/month per user for inclusive minutes to specific countries
- Call recording storage: Often included on mid-tier plans; dedicated compliance recording may cost £3 – £5/user/month
- Handsets: IP desk phones range from £60 (entry-level) to £350 (executive touchscreen). Many providers offer rental from £3/month per handset
- Business mobile integration: If your workforce is mobile-heavy, pair with the right business mobile plan to unify fixed and mobile under one system
For a comprehensive view of business phone line costs and options, our dedicated guide covers line rental, call charges and bundled packages in detail.
Key Features to Look For
Not all office phone systems are created equal. When evaluating providers, prioritise these features — they deliver the biggest productivity and customer-experience gains for UK businesses:
Auto-Attendant (Virtual Receptionist)
Greets callers with a professional menu (“Press 1 for Sales, 2 for Support…”) and routes them to the right team without human intervention. Essential for businesses that handle high call volumes or want to project a larger, more professional image.
Intelligent Call Routing
Goes beyond basic ring groups. Modern routing engines use time-of-day rules, skill-based allocation, geographic routing and even AI intent detection to connect callers with the best-placed agent. This reduces wait times and boosts first-call resolution.
Voicemail-to-Email
Converts voicemail messages into audio files (or AI-generated transcriptions) and delivers them straight to your inbox. Staff can triage messages on the go without dialling into a voicemail box — a small feature that saves significant time across a team.
CRM Integration
When your phone system talks to your CRM (Salesforce, HubSpot, Microsoft Dynamics, Zoho), inbound calls trigger automatic screen pops showing the caller’s history, open tickets and account value. Outbound click-to-dial from CRM records eliminates manual dialling errors and speeds up sales cadences.
Mobile App
A dedicated mobile app lets staff make and receive calls on their business number from any location using their smartphone. The caller always sees your main office number — never a personal mobile. This is non-negotiable for hybrid and remote teams.
Call Recording
UK financial services firms are legally required to record calls under FCA regulations, but call recording is valuable in any sector for training, dispute resolution and compliance. Look for systems with automatic recording, searchable archives and secure cloud storage.
Analytics and Reporting
Real-time dashboards showing call volumes, wait times, missed-call rates and agent performance give managers the data they need to optimise staffing and service levels. Advanced platforms add AI-driven sentiment analysis and trend forecasting.
Office Phone Systems for Remote & Hybrid Teams
The way UK businesses work has changed permanently. According to the ONS, over 40% of UK workers spent at least part of their week working from home in 2025, and that figure continues to grow. Your office phone system needs to reflect this reality.
Cloud-based office phone systems are purpose-built for distributed teams. Here’s why:
- Work-from-anywhere extensions: Every user gets a softphone (desktop app) and mobile app that mirrors their desk phone — same number, same features, same call quality. Whether they’re at the office, at home or on a train, they’re fully connected.
- Unified presence: Colleagues can see who’s available, busy or in a meeting in real time, reducing wasted call attempts and “phone tag”.
- Seamless call handoff: Start a call on your desk phone, transfer it to your mobile as you leave the office — the caller never notices.
- Centralised management: IT admins manage every user, every site and every device from a single web portal. Adding a new remote worker takes minutes, not days.
- Consistent caller experience: Every inbound call hits the same auto-attendant and routing rules regardless of where your team is physically located. Your customers get the same professional experience every time.
If your workforce splits time between office and home — or you have staff who travel frequently — pairing a cloud phone system with competitive business mobile deals ensures seamless connectivity across every device.
Ready to upgrade your office phones?
Get a free, no-obligation quote for a modern cloud phone system tailored to your business.
How to Choose the Right Office Phone System
With so many options on the market, a structured approach cuts through the noise. Follow these six steps:
Step 1: Audit Your Current Setup
Document what you have today — number of lines, handsets, monthly spend, contract end dates and any known pain points. This baseline tells you exactly what you’re replacing and what savings to target.
Step 2: Define Your Requirements
List the features your business genuinely needs versus “nice to haves.” A 10-person accountancy firm has very different requirements from a 200-seat contact centre. Focus on call volumes, integration needs, remote working requirements and compliance obligations.
Step 3: Assess Your Internet Connection
Every VoIP and cloud system depends on reliable broadband. As a rule of thumb, budget 100 Kbps of dedicated bandwidth per concurrent call. If your current connection is marginal, factor in a broadband upgrade or a dedicated SIP trunk as part of the project.
Step 4: Compare Providers
Request quotes from at least three providers. Compare not just headline per-user pricing but also setup fees, contract length, included minutes, support SLAs and exit clauses. Our best business phone systems roundup is a solid starting point.
Step 5: Run a Pilot
Most cloud providers offer a free trial or pilot period. Test call quality, mobile app reliability and admin portal usability with a small group before committing the entire business. Pay particular attention to call quality during peak broadband usage hours.
Step 6: Plan the Migration
Number porting, handset deployment and user training all need scheduling. A good provider will project-manage the migration for you — including out-of-hours cutovers to minimise disruption. Ask about parallel running (keeping old and new systems live simultaneously) during the transition.
Frequently Asked Questions
What is the best office phone system for a small business in the UK?
For most small businesses (under 50 users), a hosted VoIP or cloud phone system offers the best balance of cost, features and flexibility. There’s no expensive hardware to buy, you can scale users up or down as needed, and monthly costs start from around £8 per user. Read our small business phone system guide for tailored recommendations.
How much does a business phone system cost per month in the UK?
Monthly costs typically range from £8 to £25 per user depending on the platform and feature tier. A standard cloud phone system for a 20-user office usually costs between £280 and £400 per month. Setup costs for cloud systems are minimal — often under £300 for the entire deployment.
Can I keep my existing phone numbers when switching systems?
Yes. Number porting is standard practice in the UK and is regulated by Ofcom. Your new provider will handle the porting process, which usually takes 5 to 10 working days. There’s rarely a charge, and your callers won’t notice any change.
Do I need special internet to run a VoIP phone system?
You need a stable broadband connection with sufficient bandwidth — roughly 100 Kbps per concurrent call. For most offices, a standard fibre connection (FTTP or FTTC) is more than adequate. Larger sites with 50+ concurrent calls should consider dedicated leased lines or SD-WAN for guaranteed quality of service.
What happens to my office phones during the PSTN switch-off?
BT Openreach is switching off the UK’s traditional telephone network by January 2027. After that date, PSTN and ISDN lines will no longer work. If you haven’t already migrated to a VoIP or cloud-based system, you need to begin planning now. Our VoIP vs landline guide explains the migration process step by step.