Best business phone systems
Quo, JustCall and Nextiva compared on per-user price, what's actually included, and where each one gates API and AI features.
Quo wins for a small team on price and inclusions: it's the cheapest of the three, includes an API on every tier, and names a Claude and ChatGPT MCP connection directly. Nextiva wins instead for a larger organization that needs a full contact-center feature set and is willing to pay for its top tier to reach API access.
The short answer
- Quo (formerly OpenPhone) starts at $15/user/month (Starter, annual) and includes its API and an explicit 'ChatGPT / Claude MCP' connection on all tiers, per quo.com/pricing.
- JustCall's Team plan is $29/user/month (annual, minimum 2 licenses) with unlimited outbound minutes across Europe and unlimited inbound, per justcall.io/pricing.
- Nextiva's Small Business plans start at $15/user/month (Core, annual) but gate full API access to its Premium enterprise contact-center tier only, per nextiva.com/pricing.html.
Business phone systems compared
| System | Starting price | API access | AI/MCP | Best for | Not for |
|---|---|---|---|---|---|
| Quo | $15/user/mo (Starter, annual) | Included on all tiers | 'ChatGPT / Claude MCP' named as included | A small team wanting the cheapest entry price with an API and MCP included | A team needing a full contact-center feature set at scale |
| JustCall | $29/user/mo (Team, annual, min 2 seats) | Included from Team tier, higher limits on Business | AI Voice Agent add-on ($0.99/min pay-as-you-go) | A phone-first team wanting AI voice calling bundled with texting | A team on a tight budget that finds the AI voice add-on too expensive per minute |
| Nextiva | $15/user/mo (Core, annual) | Premium enterprise tier only | 'XBert AI Receptionist' add-on from $99/mo | A larger organization needing enterprise contact-center features | A small team that wants API access without an enterprise contract |
Figures checked on quo.com/pricing, justcall.io/pricing and nextiva.com/pricing.html, September 2026. OpenPhone's pricing URL now redirects to quo.com following the product's rebrand.
What each one is actually built for
Quo
The most straightforward of the three on price and what's included: API access on every tier, unlimited calling and messaging to the US and Canada, and an explicit Claude and ChatGPT MCP connection listed as a feature rather than buried in documentation. Its Business tier adds AI call summaries and CRM integrations with HubSpot and Salesforce. Not for: a larger organization needing dedicated contact-center routing and reporting beyond a small team's needs.
JustCall
Structured as an AI communication suite rather than a pure phone system, with a dedicated SalesPro tier built for high-volume outreach and unlimited calling. Its AI Voice Agent is a genuinely separate paid add-on rather than bundled: Agent Lite runs $99/month for 100 minutes, Agent Max $249/month for 300 minutes. Not for: a team price-sensitive about per-minute AI voice costs, which run well above dedicated voice-AI platforms.
Nextiva
The most enterprise-oriented of the three, with a dedicated contact-center product line (Essential from $75/agent/month, Professional and Premium custom) sitting above its Small Business plans. Full API access is reserved for Premium, which makes Nextiva a weaker fit for a small team wanting to build custom integrations early. Not for: a small team wanting API access without committing to the top tier.
When none of these is the answer
A one- or two-person business fielding a handful of calls a day does not need a dedicated business phone system. A personal number with call forwarding, or a free tier from any of these providers if one exists, covers that volume without a monthly per-user cost.
Disclosure: SalesCrew is our product. It is not a phone system; it runs outbound calls through Vapi as one channel today, and phone numbers, inbound routing and native SMS are on the roadmap, not shipped. A team wanting a phone number and a dialer today should choose from the systems compared above; SalesCrew is not a candidate in this category yet.
Questions
- What happened to OpenPhone?
- OpenPhone rebranded to Quo. Its old pricing URL now redirects to quo.com/pricing, and the product itself is unchanged in substance as far as this comparison could confirm; the name is the only thing that changed.
- Which of these includes a Claude or ChatGPT connection?
- Quo lists 'ChatGPT / Claude MCP' explicitly as an included feature on its pricing page, marked as new. JustCall and Nextiva's pricing pages did not name an MCP server at the time this was checked.
- Is API access included on every plan?
- Not for Nextiva. Full API access on Nextiva's pricing page is listed only in its Premium enterprise contact-center tier, not in its Small Business plans. Quo lists its API on all tiers.
- How much does an AI voice add-on cost on top of a phone plan?
- It varies widely. Nextiva's AI receptionist add-on starts at $99/month. JustCall's AI Voice Agent runs $0.99/minute pay-as-you-go, or $99/month for 100 minutes on its Lite package, both of which are considerably more per minute than a dedicated voice-AI platform like Vapi at $0.05/minute.