3CX

Dialpad

Dialpad is a cloud business communications platform combining VoIP calling, SMS, video meetings, and a contact center product into one workspace, with real-time AI transcription and coaching layered across calls and meetings. It positions itself around agentic AI features that can autonomously handle tasks like booking appointments or processing simple requests during support conversations. The platform is split into several products: Dialpad Connect for unified business communications, Dialpad Support for contact centers, and Dialpad Sell for outbound sales teams, each sharing the same AI transcription and analytics engine and integrating with tools like Salesforce, Zendesk, and Microsoft Teams.

Vonage Business Communications

Vonage Business Communications is a unified communications platform delivering VoIP calling, SMS, team messaging, and video conferencing from one system. It supports desktop and mobile apps so employees can make and receive business calls from virtually any device, with features like virtual receptionist, call recording, and CRM integrations aimed at small and mid-size businesses.

Aircall

Aircall is a cloud phone and customer communications platform built for sales and support teams. It provides VoIP calling, SMS, and shared team inboxes alongside AI features such as live call coaching, automatic transcription, and autonomous AI voice agents that can handle routine customer interactions end to end.

RingCentral

RingCentral is a cloud unified-communications platform (branded RingEX) used by over 600,000 businesses for business phone calls, SMS, team messaging, and video meetings in one subscription. It layers AI features on top of core telephony, including an AI Receptionist for automated call handling, an AI Virtual Assistant for meeting notes and translation, and conversation analytics/coaching. Beyond RingEX, RingCentral offers RingCX, a cloud contact center product for omnichannel customer support and outbound dialing. The platform runs on a global network with 99.999% claimed availability across 100+ countries and holds HIPAA, GDPR, SOC 2, and PCI DSS compliance, with 330+ third-party integrations including CRM tools like Salesforce and HubSpot.

Quo

Quo, rebranded from OpenPhone in September 2025, is a VoIP-based business phone system that gives teams shared numbers, calling, and SMS/MMS messaging in one collaborative inbox. Multiple teammates can see and respond to the same business number's calls and texts, with routing rules to direct incoming contacts to the right person. Quo layers an AI agent called Sona on top of the phone system to answer calls automatically, transcribe conversations, and summarize them, along with call recording and analytics. It is used mainly by startups and small businesses that need a professional, multi-line phone presence without deploying a traditional PBX, and it integrates with common CRMs like HubSpot and Salesforce on its higher tiers.

Allo

Allo is a cloud business phone system built around an AI receptionist that answers, routes, and summarizes every call in real time. It records and transcribes conversations, drafts post-call emails and texts, and pushes structured notes straight into the CRM so reps do not have to log calls manually. Built for sales, support, and service teams, Allo bundles unlimited calling and texting, an AI-powered IVR, and a power dialer for outbound campaigns into one flat per-user price. It integrates with tools like HubSpot, Salesforce, and Zapier, making it a fit for teams that want a phone system that already speaks CRM.