The fastest way to get Fin Voice live and integrated with your existing phone system is by using PSTN (Public Switched Telephone Network) call forwarding. This method works universally with any telephony provider and is the recommended entry point for pilots and early deployments.
What is Fin Voice?
Fin Voice is Intercom’s AI Agent for phone support. It answers calls instantly, resolves questions using your help content, and can seamlessly hand off the call to a human teammate with full context when needed.
Fin Voice is designed to integrate with any existing telephony provider, allowing you to keep your current phone system while adding powerful AI-powered support.
How the integration works
This setup uses standard PSTN forwarding to route incoming calls from your telephony provider to a dedicated Intercom number for Fin Voice. It does not require SIP (Session Initiation Protocol), which is why it is universally supported.
Why we recommend PSTN for trials
PSTN forwarding is the recommended entry point for pilots and early-stage deployments for two main reasons:
It is the fastest way to get customers live.
It is universally supported by every platform and requires minimal setup.
Setting up the Fin Voice call flow
Prerequisites
To set up this integration, you'll need the following:
Requirement | Description |
Intercom workspace | Fin Voice must be enabled and hosted in the US, EU, or AU region. |
Intercom admin access | Permissions are required to set up and manage Fin Voice. |
Knowledge base | Fin needs access to rich, up-to-date support content. |
Zendesk admin access | Ability to edit call routing or forwarding rules in your external provider. |
Zendesk phone numbers | Active inbound numbers, specifically a Main Support Line and an Escalation Line. |
Optional: IVR workflow with HTTP request capability | Required only if you want to use the Fin Voice API to pass summaries, transcripts, and intent to your agents. Your provider must support making HTTP requests from an IVR or call routing workflows. |
1. Test Fin Voice
You can simulate calls in-browser using the Voice testing tab before involving any real customers.
Go to Fin AI Agent > Deploy > Phone > Voice testing.
Click Test.
Wait for Fin to greet you, and then begin speaking normally. Allow your browser access to your microphone if prompted.
Tip: This test allows you to hear Fin answer using your own support content, switch voices, and preview greetings and escalation rules exactly as callers would hear them.
2. Create a Fin Voice line
When you're ready to set up a live phone line, you'll purchase a number from Intercom that your provider will forward calls to.
Navigate to Fin AI Agent > Deploy > Phone > Set Fin Live.
Click New line.
Select External provider and hit Next.
Give the line a name (e.g., "Fin Voice").
Under 'Where will you forward calls from?', select From a phone number (PSTN), then choose Next.
Select Purchase to acquire a US local phone number provided through Intercom Phone.
Note: When calls are forwarded over PSTN, Intercom Phone usage charges apply. These charges include a monthly fee for the US local number, and inbound/outbound per-minute charges. These are separate from Fin Voice's per-resolution pricing.
3. Configure Fin’s behavior
You can customize how Fin operates before integrating with your telephony provider.
Open the line you just created in Fin AI Agent > Deploy > Phone > Set Fin Live.
Review and adjust these optional settings:
Office hours: Choose when Fin should answer calls (defaults to 24/7).
Voice, language, and greetings: Select Fin's voice, language, and customize the greeting.
Audiences: Restrict which support content Fin can use by targeting specific callers or phone numbers.
Guidance: Set rules for Fin's communication style and when it should escalate.
Category Detection: Enable AI-based topic classification for routing or reporting.
CSAT: Enable keypad ratings (1–5) for resolved calls.
Enable recordings and transcripts
To review customer interactions and see how Fin handled each call, enable recordings and transcripts.
Enable the toggles for recordings, transcripts, and call summary.
Note: This is a global setting for all Phone calls. It's not possible to only enable recordings or transcripts for some calls.
4. Prepare your Zendesk numbers
Confirm you have two distinct lines ready in Zendesk:
Main Support Line: Your customer-facing number.
Escalation Line: The number used for human handoff from Fin.
Do not redesign your existing routing; simply use your current numbers to maintain consistency.
5. Forward calls from Zendesk to Fin Voice
Now, configure Zendesk to send inbound calls to Fin.
In Zendesk, go to Admin Center > Channels > Talk > Lines.
Select your Main Support Line and open the Routing tab.
If IVR is enabled, open your active IVR menu and edit the route for inbound calls.
Set the destination to Route to > Phone number.
Enter your Intercom Fin Voice number (include the country code) and click Save.
6. Configure escalation back to Zendesk
If Fin cannot resolve the issue, it needs to send the caller back to your human agents in Zendesk.
In Intercom, navigate to Fin AI Agent > Deploy > Phone > Set Fin Live.
Under the section If Fin can’t resolve the conversation, select Forward the call.
Enter your Zendesk Escalation Line number.
Enable Close the conversation when the call is forwarded and click Save.
No additional configuration is needed in Zendesk if your escalation number already routes to your agents.
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