Two platforms dominate the UK business phone system market in 2026: 3CX and Microsoft Teams Phone. Both are capable, both are widely deployed — but they suit very different types of business.

3CX: The Flexible, Cost-Effective PBX

3CX is an open-standard IP PBX that runs on Windows, Linux, or in the cloud. It supports standard SIP trunks, meaning you choose your own UK telecoms provider and aren’t locked into a single vendor’s pricing.

Key strengths:

• Lower total cost of ownership — bring your own SIP trunk, no per-user Microsoft licensing
• Full PBX feature set: IVR, call queues, ring groups, call recording, wallboards
• Can be self-hosted or hosted in the cloud
• Excellent mobile apps for iOS and Android
• Integrates with Salesforce, HubSpot, and Zoho CRM

Best for: Businesses that want full PBX control, lower call costs, and flexibility. Particularly strong for 10–200 users, call centres, or those who want to avoid vendor lock-in.

Microsoft Teams Phone: The Microsoft-First Option

Teams Phone adds PSTN calling to Microsoft Teams — your staff make and receive calls directly within the Teams app they already use for chat and video.

Key strengths:

• Single app for calls, meetings, chat, and file sharing
• Deep Microsoft 365 integration: calendar, contacts, presence all unified
• Easy to manage through Microsoft 365 Admin Centre
• Two PSTN options: Operator Connect (simpler) or Direct Routing (more flexible)

Best for: Businesses already embedded in Microsoft 365 who want simplicity and a single vendor relationship.

Quick Comparison

Feature	3CX	Teams Phone
Monthly cost per user	£3–8	£8–18
Hardware flexibility	High	Medium
Call routing complexity	Excellent	Good
Microsoft 365 integration	Good	Native
Self-hosted option	Yes	No
Setup complexity	Medium	Low

Our Recommendation

If your business lives in Microsoft Teams and you want the simplest possible setup, Teams Phone is hard to beat. If you want lower costs, more control, and a feature-rich PBX, 3CX is the stronger choice for most UK SMEs.

At Just Business Phones, we deploy and support both platforms and will help you find the right fit before you commit to anything.

Ready to upgrade your business phone system? Get in touch with Just Business Phones today for a free consultation — we’ll help you find the right solution at the right price.