VoIP vs Microsoft Teams Phone: Which Is Right for Your Business?
Microsoft Teams Phone is a real product. It works. For the right business, it makes sense.
But a lot of UK businesses end up paying for it when they don't need to — because it came bundled with something else, or because IT recommended it, or because nobody stopped to check whether a dedicated VoIP system would do the job better and cheaper.
This post cuts through the noise. We'll look at what each option actually costs, what each does well, and who each one is genuinely suited to.
What Is Microsoft Teams Phone?
Microsoft Teams Phone (previously called Microsoft 365 Business Voice) is an add-on that turns Teams into a phone system. It lets you make and receive external calls through your Teams app using a real phone number.
It sits on top of Microsoft 365. You can't just buy Teams Phone on its own — you need an active Microsoft 365 subscription first.
Once set up, it integrates with your existing Teams environment. Calls, chats, and meetings all live in the same interface. If your team already lives in Teams, that's a genuine convenience.
What Is a Dedicated VoIP Phone System?
A dedicated VoIP provider — like VoIPninjas — gives you a phone system that runs over the internet, independently of any other software platform.
You get a phone number (or bring your existing one), a desktop or mobile app, and features like auto-attendant, call recording, and call routing. The system doesn't depend on Microsoft, Google, or any other ecosystem. It works on any device with an internet connection.
The Real Cost of Microsoft Teams Phone
This is where a lot of businesses get caught out.
Teams Phone isn't one cost. It's a stack of costs.
First, you need a Microsoft 365 subscription. Depending on the plan, that's roughly:
- Microsoft 365 Business Basic: ~£5.10/user/month
- Microsoft 365 Business Standard: ~£10.30/user/month
- Microsoft 365 Business Premium: ~£18.60/user/month
On top of that, you add the Teams Phone licence. Teams Phone Standard is currently around £12–15/user/month.
So your realistic all-in cost lands somewhere between £17 and £34 per user per month, before you factor in international calls or additional phone numbers.
If you're already paying for Microsoft 365 for other reasons — email, Word, SharePoint — then Teams Phone becomes more competitive, because you're spreading the M365 cost across multiple uses. But if you're buying M365 primarily to get a phone system, you're spending more than you need to.
What VoIPninjas Costs
VoIPninjas is a direct UK VoIP provider based in Christchurch, Dorset. No reseller markup. Three plans, all on 28-day rolling contracts:
- Ronin — £5.99/user/month. 100 included minutes. Good for light users or backup lines.
- Samurai — £14.99/user/month. 750 included minutes, call recording, auto-attendant, mobile app. The right plan for most small businesses.
- Shogun — £24.99/user/month. Unlimited calls to UK and 55 countries. Built for high-volume users.
No Microsoft licence required. No enterprise agreement. No IT department needed to set it up.
Side-by-Side Comparison
| Feature | Microsoft Teams Phone | VoIPninjas Samurai (£14.99) |
|---|---|---|
| Monthly cost (phone system only) | ~£12–15/user + M365 licence | £14.99/user all-in |
| Total typical cost per user | £17–34/user/month | £14.99/user/month |
| Contract | Annual (standard) | 28-day rolling |
| Call recording | Yes | Yes |
| Auto-attendant | Yes | Yes |
| Mobile app | Yes (Teams app) | Yes |
| Works without Microsoft licence | No | Yes |
| Number porting | Yes | Yes |
| UK-based support | Via Microsoft partner | Yes, direct |
| Setup complexity | High (admin centre, licences, policies) | Straightforward |
| Free trial | No | 14 days, no card required |
Where Teams Phone Has the Edge
Let's be fair.
If your business already runs deeply on Microsoft 365 — your team uses Teams all day for meetings, chat, file sharing, and collaboration — then adding Teams Phone has real appeal. Everything is in one place. Your staff don't need to learn a new app. Calls, voicemails, and meeting recordings sit alongside your other Microsoft content.
For large organisations with a dedicated IT function, Teams Phone is also a reasonable choice. The admin interface is detailed and powerful. An IT team can configure call flows, manage licences, and integrate Teams Phone with other Microsoft tools like Azure Active Directory and Compliance Centre.
If you're in that world, Teams Phone makes sense.
Where Teams Phone Struggles
For most UK SMBs, the Teams Phone experience is heavier than it needs to be.
The admin portal is complex. Setting up something as basic as an auto-attendant involves navigating Microsoft's Teams Admin Centre, configuring resource accounts, assigning licences to those accounts, and linking them correctly. It's doable, but it's not quick — and if something breaks, you're raising a support ticket with Microsoft or a reseller.
You're also tied to the Microsoft ecosystem. If you ever move away from Microsoft 365, your phone system moves with it — or disappears. Teams Phone doesn't work independently.
For a 5-person professional services firm, a trades business, or a startup that wants a reliable phone system without the overhead, this is unnecessary complexity.
Who Should Use Microsoft Teams Phone
- Organisations of 50+ people already standardised on Microsoft 365
- Businesses with internal IT teams managing the Microsoft environment
- Companies where deep Teams integration (meetings, calling, messaging in one place) genuinely matters to daily operations
- Enterprises with compliance requirements that benefit from Microsoft's ecosystem
Who Should Use a Dedicated VoIP Provider
- Small and medium businesses that want a clean, working phone system without enterprise overhead
- Startups and sole traders who need a professional number and call handling from day one
- Tradespeople or field-based teams who need a mobile app that just works
- Professional services firms — solicitors, accountants, consultants — who want call recording and auto-attendant without paying for a Microsoft stack they don't fully use
- Any business that values the ability to switch provider without being locked in
A Word on Number Porting
Both Teams Phone and VoIPninjas support number porting — bringing your existing business number across.
If you've built up a presence around your current number, you don't need to change it. The porting process takes a few working days and is handled as part of your setup.
Ready to compare on your own terms? Start your free 14-day VoIPninjas trial — no card required. Try the system before you commit to anything. Start your free trial → or call us on 0330 043 2388 No tie-in, no setup fees. Most businesses are fully live within 10 working days.
Frequently Asked Questions
Can I use VoIPninjas instead of Microsoft Teams Phone?
Yes. VoIPninjas provides all the core features most businesses need from a phone system — auto-attendant, call recording, number porting, mobile app — without requiring a Microsoft licence. If your business doesn't depend on Teams for other reasons, a dedicated VoIP system is typically cheaper and simpler.
Does Microsoft Teams Phone work without a Microsoft 365 subscription?
No. Teams Phone is an add-on to Microsoft 365. You need an active M365 licence for each user before you can assign a Teams Phone licence. This is why the total cost is higher than it first appears.
Can I keep my existing phone number if I switch to VoIPninjas?
Yes. VoIPninjas supports number porting for UK numbers. You keep your existing number and it transfers across as part of the setup process. The porting timeline is typically 5–10 working days.
Is VoIPninjas suitable for businesses with remote or mobile workers?
Yes. The Samurai and Shogun plans include a mobile app, so staff can make and receive calls on their business number from any smartphone or laptop with an internet connection. There's no requirement to be in an office or on a specific device.