Top 5 Business VoIP Softphones | App Guide for Business

What Is a VoIP Softphone?

A softphone is a software application that enables voice (and often video) calls over a VoIP phone system — without physical desk phone hardware. Softphones run on laptops, desktops, tablets, and smartphones, turning any device with a microphone, speaker, and internet connection into a full-featured business phone.

For many businesses, softphones have become the primary endpoint for VoIP — reducing hardware costs, supporting remote working, and providing a seamless experience across devices.

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

Platform: Windows, Mac, iOS, Android
Cost: Included with Teams Phone licence (£6–£12/user/month)

For businesses using Microsoft Teams Phone, the Teams application itself is the softphone. Enabling a Teams Phone licence and calling plan turns Teams into a full business phone — external PSTN calls, call queues, auto-attendant, and voicemail all managed through the familiar Teams interface. Staff use the same application for meetings, messaging, and calls.

Strengths: No additional app to install, deep M365 integration, familiar interface, supports HD video, enterprise security.

Best for: Organisations running Microsoft 365 Business Premium, E3, or E5 with Teams Phone licences.

2. 3CX Softphone — Best for 3CX Deployments

Platform: Windows, Mac, iOS, Android, web browser
Cost: Included with 3CX licence

The 3CX Web Client and companion mobile app are polished, feature-rich softphones included at no additional cost with all 3CX plans. The web client runs in a browser — no installation required — and supports calls, video meetings, instant messaging, and contact integration. The mobile app brings the same functionality to iOS and Android.

Strengths: No additional cost, cross-platform, full feature access, video conferencing included, strong push notification support for mobile.

Best for: Businesses using 3CX as their VoIP platform.

3. Zoiper — Best Platform-Agnostic Softphone

Platform: Windows, Mac, Linux, iOS, Android
Cost: Free (Zoiper 5 Lite) or approximately £3–£5/user one-off (Pro version)

Zoiper is an independent SIP softphone that works with virtually any SIP-compatible VoIP platform. It is popular for businesses that need a softphone compatible with multiple systems, or those whose VoIP provider does not include a native app. The free version covers standard calls; the Pro version adds HD video, call encryption, and advanced codecs.

Strengths: Platform-agnostic, works with any SIP system, low cost, cross-platform, reliable.

Best for: Businesses with non-standard VoIP platforms, or those needing a backup softphone client.

4. Acrobits Groundwire — Best for Mobile Business Calling

Platform: iOS, Android
Cost: Approximately £7–£10 one-off purchase

Groundwire is a premium mobile VoIP client widely regarded as the best third-party SIP softphone for smartphones. Its background calling capability — reliably receiving calls even when the app is not in the foreground — is more robust than many competitors. Used extensively in industries where mobile reliability is critical.

Strengths: Best-in-class mobile background calling, reliable push notifications, strong codec support, polished UI.

Best for: Field-based or mobile staff who need reliable business call reception on their smartphone.

5. Gamma Horizon App — Best for Gamma Deployments

Platform: Windows, Mac, iOS, Android
Cost: Included with Gamma Horizon plan

Gamma Horizon includes a native softphone application for all users. The app delivers the full Gamma feature set — calls, presence, messaging — from any device. Integration with the Gamma platform is native and tight, ensuring feature parity between the desktop app, mobile app, and physical IP phone.

Strengths: Full Gamma feature set on all devices, no additional cost, UK carrier-backed reliability.

Best for: Businesses using Gamma Horizon as their VoIP platform.

Choosing the Right Softphone

In most cases, the right softphone is the one native to your VoIP platform (Teams, 3CX, Gamma). Third-party options like Zoiper and Groundwire fill gaps where the native app is inadequate for specific use cases — particularly mobile reliability. AMVIA advises on softphone selection as part of VoIP deployments.