Choosing a phone system used to be simple — call your local telecom provider, get some ISDN lines, buy some desk phones, done. Today there are dozens of options: cloud platforms, on-premise servers, hybrid setups, Microsoft Teams integration, AI features, per-user pricing vs flat-rate licensing. It’s easy to get overwhelmed.
This guide cuts through the noise. We’ll walk through the key decisions, compare the main options, and help you pick the right system for your business.
The Key Decision: Per-User vs Per-System Licensing
This is the single biggest cost difference between phone systems, and most businesses don’t realise it until they’ve already signed a contract.
Per-User Pricing (RingCentral, 8×8, Vonage, Zoom Phone)
- You pay a monthly fee per user — typically €15-35/user/month
- 10 users = €150-350/month
- 50 users = €750-1,750/month
- Costs scale linearly as you grow
Per-System Pricing (3CX, Yeastar)
- You pay a flat annual fee for the system, regardless of user count
- 3CX: €175-495/year (10-unlimited users)
- Yeastar: varies by model/plan
- Add users without increasing your licence cost
Example: A 30-person business:
- RingCentral (€20/user/month) = €7,200/year
- 3CX Pro = €295/year + SIP trunk costs (~€100-200/year)
- Difference: €6,700+ saved per year
For a detailed comparison: 3CX vs RingCentral
Step 1: Define Your Requirements
Before comparing systems, list what you actually need:
Essential Features (Every Business)
- Make and receive calls (landline, mobile, international)
- Voicemail and voicemail-to-email
- Call transfer and hold
- Mobile app (take business calls on your phone)
- Call history and basic reporting
Common Features (Most Businesses)
- IVR / auto-attendant (“Press 1 for Sales…”)
- Ring groups (multiple phones ring simultaneously)
- Call recording
- Microsoft Teams integration
- Video conferencing
- CRM integration
Advanced Features (Call Centres / Large Teams)
- Call queues with routing strategies
- Live wallboards and real-time dashboards
- Advanced call reporting with SLA tracking
- Whisper, barge, and call coaching
- Skills-based routing
- Workforce management
Industry-Specific
- Hospitality: Room service integration, wake-up calls, guest extensions
- Healthcare: HIPAA compliance, on-call routing
- Legal: Call recording with tamper-proof storage, per-client billing
- Retail/Cafés: WhatsApp ordering integration
Step 2: Choose Your Deployment Model
| Model | How It Works | Best For |
|---|---|---|
| Cloud PBX | Hosted in the cloud, managed by provider | Businesses without IT staff, remote teams |
| On-Premise PBX | Server in your office, you manage it | Compliance-heavy industries, full data control |
| Hosted VoIP | Cloud-only, per-user subscription | Small teams wanting zero setup |
| Hybrid | On-premise server + cloud for remote users | Multi-location businesses |
For a detailed breakdown: Cloud PBX vs On-Premise PBX
Step 3: Compare Platforms
Tier 1: Open-Platform PBX (Our Recommendation)
These platforms give you control over your system, choice of SIP provider, and flexible deployment:
- Per-system licensing (not per-user)
- Free plan for up to 10 users
- Cloud, on-premise, or self-hosted
- Built-in video conferencing, chat, and CRM integration
- Microsoft Teams integration via Direct Routing
- Best for: businesses of all sizes, especially those who want to avoid per-user costs
- Cloud or on-premise (hardware appliances available)
- Linkus UC app for desktop and mobile
- Built-in contact centre features
- Strong hotel/hospitality features
- Best for: businesses wanting a polished all-in-one solution
For a head-to-head comparison: Yeastar vs 3CX
Tier 2: Hosted VoIP (Per-User)
These platforms are simpler but more expensive long-term:
RingCentral
- Per-user pricing (€20-35/user/month)
- All-in-one: voice, video, messaging
- No SIP trunk flexibility — locked to their network
- Best for: small teams who want zero technical involvement
Zoom Phone
- Per-user pricing (€10-20/user/month)
- Tight Zoom Meetings integration
- Limited call centre features
- Best for: businesses already heavily using Zoom
8×8
- Per-user pricing (€15-40/user/month)
- Good international calling plans
- Contact centre features in higher tiers
- Best for: businesses with heavy international call volume
Tier 3: Microsoft Teams Calling
If your business lives in Teams and you just need basic calling:
Microsoft Teams + Direct Routing
- Use your existing Teams environment
- Connect to PSTN via SIP trunking and Direct Routing
- Much cheaper than Microsoft Calling Plans
- Best for: Microsoft-first businesses, companies with Teams already deployed
Step 4: Consider Total Cost of Ownership
Don’t just compare monthly fees. Look at the full picture over 3 years:
| Cost Factor | Per-User (e.g., RingCentral) | Per-System (e.g., 3CX) |
|---|---|---|
| Platform licence | €20/user/month × users | €295-495/year flat |
| SIP trunking | Included (inflexible) | Separate (choose your provider) |
| Call rates | Set by platform | Set by SIP provider (usually cheaper) |
| Phones/hardware | Same | Same |
| Setup/migration | Often “free” (built into monthly cost) | One-time cost via partner |
| Adding users | Increases monthly bill | No additional licence cost |
| 3-year cost (30 users) | €21,600-37,800 | €1,500-3,000 + SIP costs |
Step 5: Plan Your Migration
Switching phone systems doesn’t have to be disruptive:
- Audit your current setup — how many users, numbers, lines, and what features are you actually using?
- Choose your new platform — based on the criteria above
- Get a SIP trunk — ITelecoms provides SIP trunking compatible with 3CX, Yeastar, and all major platforms
- Port your numbers — keep your existing phone numbers (5-10 working days)
- Configure the new system — extensions, IVR, queues, reporting
- Test — make test calls before going live
- Go live — switch over, usually overnight
- Train your team — 30-minute session covers everything most users need
The entire process typically takes 1-3 weeks from decision to go-live, depending on number porting timelines.
Frequently Asked Questions
What’s the cheapest business phone system?
3CX StartUP is free for up to 10 users — genuinely free, no trial. Add a SIP trunk for €5-15/month and you have a complete business phone system for under €20/month.
Can I use my mobile as my business phone?
Yes. Both 3CX and Yeastar have mobile apps that show your business number as caller ID. You can take business calls from anywhere without giving out your personal number.
Do I need physical desk phones?
No. Softphone apps (desktop and mobile) work perfectly. Many businesses are going desk-phone-free, especially with hybrid/remote working. If you want desk phones, Yealink and Fanvil offer excellent options from €50-200.
How long does it take to switch?
1-3 weeks from decision to go-live. The longest part is number porting (5-10 working days). System setup can be done in a day.
What if I choose wrong?
With open-platform systems like 3CX and Yeastar, you own your phone numbers (they’re with your SIP provider, not the PBX vendor). You can switch PBX platforms without losing your numbers or starting over.
Need help choosing the right phone system? Contact ITelecoms — we’ll assess your requirements and recommend the best solution. We deploy 3CX, Yeastar, Microsoft Teams Direct Routing, and SIP trunking — all under one roof.