Top 5 Business VoIP Softphones | App Guide for Business

A softphone removes the desk handset from the equation. For most UK businesses we deploy, it is now the primary way staff make and take calls — at a desk, at home, or on the move. Below we compare the five we see most often on a business VoIP rollout, including who each one suits and what it actually costs.

What Is a VoIP Softphone?

A VoIP softphone is a software app that makes and receives business calls over the internet using a device's microphone and speaker. It runs on Windows, Mac, iOS and Android, replacing a physical desk phone. You get the full feature set — transfer, hold, voicemail, call recording — with no handset to buy or maintain.

Softphones have changed how UK teams work. They cut hardware spend, support hybrid and remote staff, and give one consistent calling experience across every device. The trade-off is that call quality now depends on the device and the connection, so a decent headset and a stable line matter more than ever.

1. Microsoft Teams (Teams Phone) — Best for Microsoft 365 Users

For any business already on Microsoft 365, Teams is the softphone. Add a Teams Phone licence and a calling plan, and Teams handles external PSTN calls, call queues, auto-attendant and voicemail — inside the app staff already use for chat and meetings. No second app to learn or support.

• Platform: Windows, Mac, iOS, Android
• Cost: Included with a Teams Phone licence (around £6–£12/user/month)
• Strengths: No extra app, deep Microsoft 365 integration, HD video, enterprise-grade security
• Best for: Organisations on Microsoft 365 Business Premium, E3 or E5

Microsoft documents the full Teams Phone calling architecture on Microsoft Learn, and licensing sits alongside the wider Microsoft 365 plans. Because calls run through the same tenant as your email and files, security and identity are managed in one place — read how we approach Microsoft Teams calling and VoIP with Microsoft 365.

2. 3CX Softphone — Best for 3CX Deployments

If you run 3CX, the included web client and mobile app are among the most capable softphones available — at no extra cost. The web client runs in a browser with nothing to install and supports calls, video meetings, instant messaging and contact integration. The iOS and Android apps bring the same features to mobile.

• Platform: Windows, Mac, iOS, Android, web browser
• Cost: Included with the 3CX licence
• Strengths: No additional cost, cross-platform, full feature access, video included, strong mobile push notifications
• Best for: Businesses using 3CX as their VoIP platform

The browser client is the standout: staff can pick up calls from any machine without an install, which makes onboarding and remote work simple. Push notification handling on mobile is robust, so calls ring reliably even when the app is closed.

3. Zoiper — Best Platform-Agnostic Softphone

Zoiper is an independent SIP softphone that connects to almost any SIP-compatible VoIP platform. It is the practical choice when your provider has no native app, or when you need one client that works across several systems. The free Lite edition covers standard calls; the Pro version adds HD video, call encryption and advanced codecs.

• Platform: Windows, Mac, Linux, iOS, Android
• Cost: Free (Zoiper 5 Lite) or roughly £3–£5/user one-off for Pro
• Strengths: Works with any SIP system, low cost, genuinely cross-platform, reliable
• Best for: Businesses with non-standard VoIP platforms, or anyone needing a backup client

Zoiper earns its place as the universal fallback. When a native app falls short on a specific device or OS, a SIP client like Zoiper fills the gap without locking you to a single vendor.

4. Acrobits Groundwire — Best for Mobile Business Calling

Groundwire is a premium mobile SIP client widely regarded as the best third-party softphone for smartphones. Its background-calling engine reliably receives calls even when the app is not open — noticeably more dependable than many rivals. That reliability is why field and on-call teams pick it.

• Platform: iOS, Android
• Cost: Approximately £7–£10 one-off purchase (typical 2026 UK pricing)
• Strengths: Best-in-class mobile background calling, dependable push notifications, strong codec support, polished interface
• Best for: Field-based or mobile staff who need reliable business calls on a smartphone

If mobile reliability is the deciding factor, Groundwire is the answer. It pairs well with a hosted platform when the native mobile app cannot guarantee a call lands every time.

5. Gamma Horizon App — Best for Gamma Deployments

Gamma Horizon ships a native softphone for every user. The app delivers the full Horizon feature set — calls, presence and messaging — from any device, with tight integration to the underlying UK carrier platform. Feature parity across the desktop app, mobile app and physical IP phone keeps the experience consistent.

• Platform: Windows, Mac, iOS, Android
• Cost: Included with the Gamma Horizon plan
• Strengths: Full Horizon feature set on all devices, no additional cost, UK carrier-backed reliability
• Best for: Businesses using Gamma Horizon as their VoIP platform

Because the app is built around the same platform that carries your numbers, there is no compatibility guesswork. For UK businesses that want carrier-grade resilience with a single supplier, it is a straightforward fit.

How Do the Top 5 Softphones Compare?

The fastest way to choose is to start with your platform, then check device coverage and cost. Native apps (Teams, 3CX, Gamma) win on integration; third-party clients (Zoiper, Groundwire) win where you need flexibility or rock-solid mobile reception.

How Do You Choose the Right Softphone?

In most cases the right softphone is the one native to your VoIP platform — Teams, 3CX or Gamma. Third-party options such as Zoiper and Groundwire exist to fill specific gaps, usually around mobile reliability or odd device support. Pick the platform first, then the client.

This is where having one accountable provider pays off. AMVIA advises on softphone selection as part of every VoIP build — matching the client to your hosted phone system, your devices and your security posture, then handling VoIP security so calls stay protected. One provider. Security-first. Microsoft-certified. For teams that want calls, chat and meetings in one stack, our UCaaS for SMEs approach brings them together.