3CX or Teams Phone: which cloud phone system suits your business?
When I recommend 3CX, when Teams Phone, what a cloud phone system costs per workstation and where a switch can go wrong: lessons from around 20 phone systems I have set up.
Choosing a new cloud phone system is about more than the number of extensions: how should calls be routed, where do your staff work, and which devices should stay? I have set up around 20 phone systems so far, mostly with 3CX and in some cases with Teams Phone. Below I explain when I recommend which, and what should be settled before you decide.
3CX, Teams Phone or Cloud PBX: who needs what
Comparisons often mix up two things. The phone system distributes calls. The SIP trunk is the connection that links the system to the telephone network, and your calls are billed through it. 3CX and Teams Phone are phone systems. peoplefone is a SIP trunk provider. Telekom Cloud PBX brings both from a single source.
A good fit for customers with simple call flows. It is affordable and can run on your own servers, so you decide where and how it is operated. It is also intuitive enough for staff with no interest in technology. The larger editions can be customised extensively and handle complex call routing too. The AI integration now ranges from routing to transcription and reports.
Teams Phone adds calling to and from the public telephone network to Microsoft Teams, with a main number, queue and voicemail directly in the Teams client. The licences and the connection to the telephone network have to match. As soon as the configuration gets more complex, Teams Phone is, in my experience, more limited and more cumbersome than 3CX.
System, line and numbers come from the network operator. I look after one customer who uses it. In my view it fits when that is exactly what you want and requirements stay modest. If you want to customise things, you reach its limits sooner than with 3CX.
Not a phone system but a SIP trunk provider. I like to combine peoplefone with 3CX because support responds quickly and the pricing is transparent and affordable.
So Teams Phone is not a worse product, just a different one. I chose it deliberately for a non-profit organisation with a distributed team. They wanted a main number with a queue, with no hardware and no ties to a location, and everyone already worked in Teams. You can see what that looks like in the case study Microsoft 365 and telephony in Teams for a non-profit organisation.
What does a cloud phone system cost?
The price per workstation varies widely, and the biggest factor is how the system is run. With 3CX there are three options:
- Self-hosted: the system runs on a server of your own. This is the cheapest option, and you decide where the system and its data live. That does not make it automatically compliant with data protection law; that depends on how it is set up and run. In return, you or your IT provider must keep server and system running.
- Managed hosting: a provider runs the system on its servers and takes care of updates and monitoring. I run 3CX for my customers on my own servers.
- As a service (SaaS): 3CX hosts it. According to the price list, this costs €430* a year for up to 16 simultaneous calls, on top of the licence.
The licence prices are public. 3CX charges per system based on the number of simultaneous calls, not per person. According to the price list, the PRO edition costs €380* a year for 8 simultaneous calls and €760* for 16, excluding VAT. As an example: for 30 employees, a 3CX system I look after comes to around €3 to €5* per person per month for server and licence. On top of that come the SIP trunk’s call charges, billed by usage.
Teams Phone, by contrast, is licensed per person. In April 2025 Microsoft raised the price of Teams Phone Standard to 10 US dollars* per user per month on an annual commitment. In euros that is around €8.70*. It requires a Microsoft 365 licence that includes Teams. For external calls you also need a Microsoft Calling Plan or a SIP trunk, for example from peoplefone or Telekom.
The switch: number porting, fax machines, door entry systems
The new provider usually carries out the number porting. I plan it, put the paperwork together and monitor the date. Once all documents are complete, porting is done within a few days to a few weeks. By law, service may be interrupted for no more than one working day when you change provider. When everything was well prepared, porting dates for my customers have so far gone without problems.
The harder part of moving to a cloud phone system is everything connected to the old system that nobody thinks of as a phone. Fax machines really are a problem, as are door entry systems and door openers that were controlled through the phone system. Before the switch I therefore record every device that dials out or takes calls through the old system. For each one I decide whether it gets an adapter, a replacement or a different route. That includes lift emergency phones and alarm systems, if there are any.
Headset, app or desk phone
Both happen, and it varies a great deal from customer to customer. My recommendation: a noise-cancelling headset on the PC or Mac, and the app on the smartphone when you are out. Then you do not need to forward calls to a mobile. Your own extension is always with you, with the same number and features as in the office. Desk phones stay where people need them day to day.
Why I plan hybrid rather than purely cloud or purely on site
As a rule, I advise neither a pure cloud nor a pure on-site system, but a hybrid solution wherever possible. If many employees work from home, the system runs in the cloud. In the office sits a session border controller, a small device that connects the phones on site to the system. Calls within the office then stay on the local network and do not have to go through the cloud. Remote workers call straight into the cloud rather than through the office line, which may be undersized or unstable.
If the office internet fails, a cloud phone system keeps running in the data centre. How you stay reachable depends on the setup: staff can use the smartphone app over mobile data, and I set up forwarding for office extensions. Desk phones connected only through the office line will not work until it is restored. Emergency calls belong in this plan too: it should be clear beforehand which devices can still make them during an outage. So that telephony runs cleanly on the office network, I give it its own VLAN. More on this under infrastructure & network.
Frequently asked questions
Is 3CX or Teams Phone cheaper?
Usually 3CX. The licence covers the whole system and depends on the number of simultaneous calls. Teams Phone is licensed per person. For 30 employees, a 3CX system I look after comes to around €3 to €5* per person per month for server and licence. Teams Phone Standard alone costs around €8.70*. Call charges come on top in both cases.
How long does number porting take?
With complete paperwork, a few days to a few weeks. The new provider usually carries out the porting itself. I plan it and monitor the date, so the system, numbers and devices are ready on the day.
Can I still be reached with a cloud phone system if the internet goes down?
Usually, yes. The system keeps running in the data centre even if the office line fails. Staff then take calls via the smartphone app, and forwarding rules set up in advance apply to extensions that cannot be reached. Phones that only run over the office line cannot be reached during that time.
* Prices net, as of September 2026. Licence prices may have changed since.
Sources
- 3CX prices (licence and hosting, excl. VAT, as of 25 September 2026): 3CX – Full Pricelist
- 3CX AI features: 3CX – AI Transcription, 3CX – AI Edition
- Session border controller, local calls on the office network: 3CX – Installing a 3CX SBC, 3CX – Run 3CX SBC on a Raspberry Pi
- Teams Phone Standard price (10 US dollars from 1 April 2025): Microsoft Tech Community – Pricing updates for annual subscriptions & Teams Phone
- Teams Phone Standard list price in euros (reseller information, as of 25 September 2026): m365.de – Microsoft Teams Phone Standard
- Prerequisites and connection to the telephone network: Microsoft Learn – Microsoft Teams add-on licenses, Microsoft Learn – PSTN connectivity options
- Provider change and number porting in Germany: Section 59 of the German Telecommunications Act (TKG)
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