Integrations / Business phone systems and carriers

Use AssistCall with Quo (formerly OpenPhone)

Keep your Quo (formerly OpenPhone) number. Forward it to AssistCall when you're busy, don't pick up or after hours, and every call gets answered, booked or turned into a message, with a summary by email.

Quo (formerly OpenPhone): App-based business phone system with shared numbers, texting and call summaries, popular with small teams that work from their mobiles.

Connects

Example call

A tenant calls a property manager's Quo number at 10 pm about a leak. The after-hours forward sends the call to AssistCall, which takes an urgent message, and a Zap adds the tenant as a Quo contact so the morning callback shows their name.

• In Quo's Call Flow Builder, send the after-hours branch of your Business hours step to a Forward call step with your AssistCall number.
• Add a Forward call step after Ring users so calls your team doesn't pick up go to the receptionist instead of voicemail.
• When AssistCall captures a lead, a Zap or Make scenario creates or updates the caller as a Quo contact, so your team sees the name on the next call or text.

How it connects

• Call forwarding: Forward your business line to AssistCall when busy, after hours or always. Works with any carrier.
• Zapier: Send AssistCall events to a Zap (Webhooks by Zapier, Catch Hook), then use the app's Zapier actions. Needs a paid Zapier plan.
• Make: Start a Make scenario with a custom webhook and use the app's Make modules.
• n8n: Start an n8n workflow with a webhook node, then call the app with its node or an HTTP request.

About Quo (formerly OpenPhone)'s API

• Self-serve API: you can create a key in your account
• Style: REST, plus webhooks
• Authentication: API key in the Authorization header (no Bearer prefix), created by a workspace owner or admin; no expiry documented
• On Zapier: yes. On Make: yes.

Owners and admins create keys under Workspace Settings > API. The current API version also requires a Quo-Api-Version header, so AssistCall reaches Quo through Zapier (Send a Message, Create or Update Contact), Make (Quo app) or n8n rather than live calls with one saved header. Texting through the API needs US carrier registration. Forwarding uses the Call Flow Builder: 'Forward all calls', a Forward call step on the after-hours branch of a Business hours step, or a Forward call step after Ring users for unanswered calls. Only US and Canadian destinations are allowed, Quo doesn't record or transcribe calls it forwards out, and each forwarded call counts double toward usage.

Not included: no one-click Quo (formerly OpenPhone) app, no listing in Quo (formerly OpenPhone)'s marketplace, no two-way sync, and no partnership with Quo (formerly OpenPhone).

Researched by the AssistCall team and checked against Quo (formerly OpenPhone)'s public pages on October 24, 2026. Quo (formerly OpenPhone) is a trademark of Quo (formerly OpenPhone). AssistCall is an independent product of Starling Global LLC and is not affiliated with, endorsed by, sponsored by or approved by Quo (formerly OpenPhone).

More Business phone systems and carriers integrations

• AT&T Business: AT&T's business wireless, fiber and phone service, which many small businesses use for the mobile or landline number printed on their trucks, cards and listings.
• Comcast Business: Comcast's internet and business phone service (Business Voice and VoiceEdge) for offices, shops and restaurants in its cable footprint.
• RingCentral: Cloud business phone system (RingEX) with calling, texting, video and team chat in one app, used by small offices up to large companies.
• Spectrum Business: Charter's internet, mobile and business phone service (Spectrum Business Voice) for small businesses in Spectrum service areas.
• T-Mobile for Business: T-Mobile's wireless and internet service for small businesses, often the owner's mobile number doubling as the business line.
• Verizon Business: Verizon's business wireless, internet and phone service, used by many small businesses whose main number is an owner's or staff member's Verizon mobile line.

All product and company names in this directory are trademarks or registered trademarks of their respective owners, used only to identify systems AssistCall can send call information to or receive information from. Their use does not imply any affiliation with or endorsement by their owners. AssistCall connects using signed webhooks, the business's own API keys, automation platforms (Zapier, Make, n8n) the business sets up in its own account, and call forwarding. AssistCall does not provide one-click connectors, marketplace apps, certifications or two-way record or calendar sync, and does not sign HIPAA business associate agreements. Vendor features, plans and API access can change; information last checked October 24, 2026.