Use AssistCall with Microsoft Outlook Calendar

AssistCall answers your business calls 24/7 and can send each call, message and booking to Microsoft Outlook Calendar through Webhook, Zapier, Make, n8n.

Microsoft Outlook Calendar: The calendar in Outlook and Microsoft 365, used by offices that run their email, meetings and scheduling on Microsoft 365.

Connects

Example call

A caller asks for a consultation on Monday at 9am. The receptionist books it and AssistCall sends appointment.booked to Zapier, which creates the event in Outlook. The attorney sees it on their Microsoft 365 calendar and gets the email summary.

Every appointment AssistCall books becomes an Outlook calendar event through Zapier's Microsoft Outlook Create Event action.
When a caller cancels, a Make scenario using the Microsoft 365 Calendar app finds the event and deletes it.
After each call.completed event from a new lead, an n8n workflow adds a follow-up event to the calendar with the call summary and recording link.

How it connects

Webhook: Signed JSON for every call, message and booking, sent to any HTTPS URL you choose.
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.
Call forwarding: Forward your business line to AssistCall when busy, after hours or always. Works with any carrier.

About Microsoft Outlook Calendar's API

Self-serve API: you can create a key in your account
Style: REST (Microsoft Graph)
Authentication: OAuth 2.0 through an app registration in Microsoft Entra ID
On Zapier: yes. On Make: yes.

A Microsoft 365 admin can register an app and grant calendar permissions themselves. Graph access tokens are short-lived, so AssistCall connects through Zapier, Make or n8n instead of live lookups during a call. Graph change notifications (subscriptions) can report new or changed events.

Not included: no one-click Microsoft Outlook Calendar app, no listing in Microsoft Outlook Calendar's marketplace, no two-way sync, and no partnership with Microsoft.

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

More Calendars and scheduling integrations

Calendly: Online scheduling links that let clients pick an open time on your calendar, used by consultants, coaches, sales teams and service businesses.
Google Calendar: Google's online calendar, included with Gmail and Google Workspace, which many small businesses use to track appointments, jobs and staff schedules.
Square Appointments: Square's booking and payments app for appointment businesses such as salons, barbershops, spas and wellness studios.
Acuity Scheduling: Online appointment scheduling from Squarespace with intake forms, packages and payments, used by solo practitioners and small service teams.
Cal.com: Open-source scheduling links and booking pages, hosted or self-hosted, used by consultants, agencies and software teams.
Microsoft Bookings: Microsoft 365's booking pages and shared appointment calendar for teams, connected to Outlook and Teams.

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.