3CX is the most-deployed business phone software in the world. Roughly 350,000 businesses across 190 countries run their phones on it, including a substantial slice of UK SMEs. Most people first hear about it via their IT-support firm, an accountancy peer, or a quote from a managed provider. Almost none of those introductions explain what 3CX really is — they pitch a package wrapped around it. This page is the explanation.
3CX is licensed phone-system software. You buy a yearly licence from 3CX, you run the software somewhere, you connect it to SIP trunks for outside calls, and you plug in handsets or use mobile and desktop apps. That's the whole thing.
3CX is software. RingCentral, 8x8, Aircall, Vonage and Zoom Phone are cloud services.
Cloud services charge you per user, per month, indefinitely, and the vendor runs absolutely everything. 3CX is software with a per-system yearly fee that scales by capacity (not by user count), and you (or a partner) own the operational layer.
Different economic model, different licence model, different relationship. The rest of this page is about what that means in practice.
Most UK businesses live in PRO. Small offices may sit on FREE. Contact centres or anyone needing AI features want AI or Enterprise Plus.
| Edition | Who it's for | What it unlocks |
|---|---|---|
| SMB FREEUp to 10 users. Maximum 3 free subscriptions per account. | Tiny offices£0 | Basic call routing, mobile app, voicemail, single IVR. Lacks recording, queues, CRM integration, deep video. Fine for a 4-person solicitor's office until growth pushes it to BASIC or PRO. |
| BASICLicensed by Simultaneous Calls (SC), not user count. 5:1 to 7:1 users-to-SC. | Reliability tierFrom £250/yr | Better IVR, manageability, and reliability. Still no recording, no advanced queues, no CRM. Most UK SMEs skip BASIC and go straight to PRO — the gap in features doesn't justify the licence saving. |
| PROThe most common SME tier in the UK. | Standard SMEFrom £330/yr | Call recording, advanced call queues, deep CRM (Salesforce, HubSpot, Dynamics), reporting and wallboards, live chat, video, switchboard, hot desking, Microsoft Teams integration. The features most SMEs actually want all sit here. |
| AIAdds the AI suite plus enterprise routing features. | Contact-centre / Teams shopFrom £480/yr | PRO plus Teams direct routing, skills-based routing, AI call transcription, AI summaries and sentiment, AI receptionist. Worth it for inbound contact-centre operations or firms already standardised on Teams as their calling client. |
| Enterprise PlusAI tier plus pre-paid transcription minutes. | Heavy AI volumeAbove AI list | AI tier with bundled transcription minutes (30k at 8 SC, 60k at 16 SC). Relevant if your monthly AI transcription would otherwise exceed the pay-as-you-go floor; otherwise AI is the right tier. |
Prices are GBP, ex-VAT, snapshot May 2026 from 3cx.com/ordering/pricing/pricelist. 3CX runs an evergreen multi-year discount (10% off 1-year, 15% off 2-year, 20% off 3-year), so a 25-user firm on PRO at 8 SC pays ~£260/yr on a 3-year deal rather than £330/yr year-to-year. Hosting is a separate line — see 3CX hosting in the UK.
The part that trips up almost every UK SME owner who reads the 3CX pricelist for the first time. You don't pay per user. You pay for SC — Simultaneous Calls — which is how many calls the system can route at the same moment.
8 SC
Recommended for a 35-user accountancy with normal call density. Not 24. Not 32.
3CX's recommended user-to-SC ratio is 5:1 to 7:1. A 35-user accountancy with normal call density typically needs 8 SC, and that's what 3CX recommends.
It is a common UK managed-provider sales tactic to quote 24 SC for 35 users. At PRO list that's £910/yr instead of £330/yr — a roughly 3× licence inflation you can't easily check without the published price list. We unpack this on the honest-pricing page.
One decision you make once. Different ops shape, different cost shape.
3CX runs on a Debian server in your office (or a small dedicated appliance like a Mini PC). You own the hardware, you keep all the call traffic on your local network, and you eat the upgrade work and physical-failure risk. Common in firms with existing IT capability or strong data-locality preferences.
3CX runs on a virtual server you rent from AWS, DigitalOcean, Hetzner, or any other cloud provider. You manage the OS, the firewall, the upgrades. Cheap (£10–25/mo VPS easily handles a 50-user system) but you own all the ops.
3CX themselves run the system for you in their data centres. Self-service via 3cx.com, separately priced from the licence (currently £245/yr for 8–16 SC, scaling up beyond that). Easy to buy, easy to scale, but you're buying two products from 3CX with no integrator handling the SIP, handsets, porting or training layers.
A UK 3CX partner (Port Phones is one) runs the whole thing for you — the licence, the hosting, the SIP trunks, the handsets, the porting from your old provider, the training, and the support when something breaks. One bill, one number to call, one accountable supplier. This is what most UK SMEs end up with.
We have a full guide to the four hosting models with UK pricing, and a separate guide to evaluating UK 3CX partners.
Three things 3CX is sometimes confused with.
The licence gives you the PBX software. You still need to buy SIP trunks from a separate provider (Gamma, Sippy, Voipfone, Vonage UK, etc.) to make and receive external calls. UK 3CX partners typically resell Gamma SIP at a markup; you can also buy direct.
3CX works with Yealink, Snom, Fanvil, Grandstream, and Polycom handsets, plus its own iOS/Android apps and a web client. You buy the handsets separately from a distributor or your managed partner.
RingCentral is a fully bundled cloud service at £20–30 per user per month. 3CX is software with a per-system yearly licence at roughly £6–10 per user per month including hosting and SIP through a managed partner. Different model, different price. See 3CX vs RingCentral for the line-by-line comparison.
The five questions UK SME buyers ask about 3CX before signing anything.
15 minutes. We size your SC band, propose a hosting model, and quote the licence + ops layer line by line. No marketing-default SKUs.
A clear picture of your current setup, the SC count you actually need, the hosting model that fits your IT preferences, and a fixed-price quote with every line item broken out. No jargon, no pressure.
+44 7909 338388
sales@portphones.co.uk
31-33 Commercial Road, Poole, Dorset BH14 0HU
Bring it. The audit doubles as a line-by-line read of someone else's quote against the same component model: licence, hosting, SIP, handsets, setup.