Leading VoIP Services for Medium-Sized Enterprises

I want to start a discussion around VoIP solutions that work well for mid-sized organisations, those managing distributed teams, growing call volumes, and evolving communication needs. Which providers actually deliver when it comes to reliability, features, and scalability?

These are a few of the top-rated platforms on G2’s VoIP category:

• Nextiva: All-in-one communication suite with VoIP, video, and collaboration tools. Is it a strong fit for hybrid teams or better suited for contact centers?
• OpenPhone: Designed for startups and scaling businesses. The UI seems clean and flexible—does it meet the needs of more complex phone workflows?
• Webex Calling: Backed by Cisco, it offers enterprise-grade call management. How intuitive is the admin side, and what’s the learning curve like for new users?
• RingEX: RingCentral’s platform is known for integrations and features, but how well does it perform for companies juggling multiple departments?
• Vonage Business Communications: Offers a strong blend of VoIP, messaging, and CRM tools. Is it still competitive in terms of support and pricing?

Would love to hear from teams using any of these. What’s worked best for call quality, team collaboration, and managing multiple lines or locations?