> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getthread.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Answer overflow & after-hours calls

> Replace voicemail with a Voice AI Overflow agent that answers after-hours calls, takes intelligent messages, and creates PSA tickets for 24/7 coverage.

[← Phase 1: Initial Configuration](/ai-agents/voice-ai-setup-phase-1-initial-configuration)

<Note>
  See the latest **Voice AI** updates in the [changelog](/changelog/q3-2026).
</Note>

## Phase 2: Overflow & After Hours

<Frame>
  <iframe src="https://www.loom.com/embed/2b88559d82ae46ddb2901d624a2364d7" width="100%" height="400" allowfullscreen />
</Frame>

<Frame>
  <img src="https://mintcdn.com/thread/yMrisProrR453qj0/images/29410872-overflow.png?fit=max&auto=format&n=yMrisProrR453qj0&q=85&s=09c26c9d540ad23eeaf3903edae3e688" alt="Overflow agent overview" width="1046" height="372" data-path="images/29410872-overflow.png" />
</Frame>

**Concept**

Replacing your static, passive voicemail box with an active AI agent that answers calls, takes intelligent messages, and creates tickets when your team is unavailable.

**Value**

This eliminates "phone tag" and ensures you never miss a revenue opportunity or urgent issue. You get 24/7 coverage without additional staffing costs, and clients feel heard rather than ignored.

**Use Cases**

* **After Hours Coverage:** Forward your calls to the Overflow number after work hours and on holidays (controlled by Microsoft hours).
* **Front Desk Overflow:** Use overflow as a front desk where technicians take no calls; they simply call back based on the ticket. This allows you to understand and prioritize responses at your own pace, saving dispatchers and techs time.

### **How to Get a Number**

<Steps>
  <Step title="Go to the Overflow tab">
    Go to the **Overflow** tab.
  </Step>

  <Step title="Request a number">
    Click **Request Number**, select your country, and confirm.
  </Step>
</Steps>

<Frame>
  <img src="https://mintlify.s3.us-west-1.amazonaws.com/thread/images/e1e7e6bc-cfimages" alt="Requesting an Overflow number" />
</Frame>

### Customize the Agent

#### Greeting

Customize your greeting so that your callers **understand what to expect.** We have found a key reason that callers might get frustrated is a lack of understanding of how this agent fits into your process.

<Frame>
  <img src="https://mintcdn.com/thread/MmA6qEMELRi-vXeU/images/efdebce9-greeti.png?fit=max&auto=format&n=MmA6qEMELRi-vXeU&q=85&s=204bbd569c68b6502b4c706a825492ae" alt="Overflow agent greeting configuration" width="623" height="250" data-path="images/efdebce9-greeti.png" />
</Frame>

<Note>
  Important:

  Do not ask what the issue is in the greeting, the agent does that by itself. Putting it here will double the question.
</Note>

#### Note Escalation Requests

Overflow doesn't escalate calls, but it can note escalation words in the ticket. **This does not automatically change ticket priority.**

#### Additional Questions

The voice agent will automatically ask the caller what their issue is, but you can customize any additional questions you want to ask. We don't recommend adding more than 2-3 questions as the call can get quite lengthy and callers can get frustrated.

#### Choose a Default Board and Source

Set your default board and source. Ideally, you have created a unique **Source** in your PSA called **"Voice AI"** (or similar) as covered in Phase 1.

Click **Save**!

### Set Up After Hours (Optional)

<Steps>
  <Step title="Go to the After Hours tab">
    Go to the **After Hours** tab.
  </Step>

  <Step title="Confirm hours sync">
    This syncs with your **Messenger Hours**.
  </Step>

  <Step title="Add a closed-hours greeting">
    Provide a custom greeting for when your business is closed. The agent will then use the Overflow agent settings for handling the call.
  </Step>
</Steps>

### Test Your Agent

#### Before connecting to your phone system, thoroughly test your agent:

<Steps>
  <Step title="Call the agent number">
    Call the agent phone number provided.
  </Step>

  <Step title="Complete about 5 test calls">
    Complete approximately 5 test calls to ensure the agent is working properly.
  </Step>

  <Step title="Review transcripts and tickets">
    Review each call's transcript and ticket creation.
  </Step>

  <Step title="Note unexpected behavior">
    Note any unexpected behavior to review with your CSM.
  </Step>

  <Step title="Proceed to phone system setup">
    When you are confident in your agent's performance, you can proceed to set up the number within your phone system.
  </Step>
</Steps>

### Expected Call Flow:

1. Caller dials the Overflow number.
2. AI greets the caller with your custom greeting.
3. AI asks what they need help with.
4. AI asks any additional custom questions you configured.
5. AI confirms the information and thanks the caller.
6. Call ends and ticket is automatically created in your PSA.

### How To Configure Your VoIP/PBX

This step determines when the AI picks up the phone. Configure your phone system to forward calls to the Thread Overflow number you received above.

#### Common Setup:

<Steps>
  <Step title="Log into your VoIP provider">
    Log into your VoIP provider.
  </Step>

  <Step title="Locate your ring group or call queue">
    Locate your **Main Ring Group** or **Call Queue**.
  </Step>

  <Step title="Find the no-answer settings">
    Find the settings for **"If no answer," "Busy,"** or **"Max wait time reached."**
  </Step>

  <Step title="Set the destination">
    Set the destination to the **Thread Overflow Number** (obtained in the "Get a Number" step).
  </Step>

  <Step title="Point after-hours logic here too">
    Ensure your **"After Hours"** logic also points to this number.
  </Step>
</Steps>

<Note>
  Note:

  For phone-system-specific forwarding instructions (RingCentral, 8x8, Microsoft Teams, Cisco, Mitel, BVoIP/3CX), see the separate **Phone System Forwarding Instructions** document.
</Note>

### Routing Gotchas

A few phone-system patterns cause avoidable problems — check these before you go live:

* **Don't create a double-ticket loop.** If your Attendant already rolls unanswered calls to Overflow (via **Use Overflow when no one is available** in Attendant settings), do **not** also point your PBX ring-group "no answer" rollover back at a Thread Voice number. Doing both sends the unanswered call back in as a **brand-new inbound call** that Thread can't tell is the same call — producing two tickets and, in some cases, two agents on the line. Let the Attendant's own overflow handle the rollover.
* **There's no "answer but skip the AI" toggle for business hours.** Voice AI doesn't have a setting to pick up a call during business hours without running the AI. Control this at the **phone-system** level: route to your team during business hours and forward to the Thread number only after hours.
* **Microsoft Teams overflow needs Pay-As-You-Go.** If a Microsoft Teams Call Queue or Auto Attendant redirects to your Thread number, the resource account needs Pay-As-You-Go / Communication Credits — since November 1, 2025 Microsoft no longer allows outbound PSTN from resource accounts on Calling Plan licenses, and the redirect silently fails without it. See [Microsoft Teams Pay-As-You-Go resource account calling](/ai-agents/microsoft-teams-pay-as-you-go-resource-account-calling).

## Next

<Card title="Phase 3: The Auto-Attendant (Walk → Run)" icon="headset" href="/ai-agents/voice-ai-setup-phase-3-the-auto-attendant-walk-run">
  Deploy the Auto-Attendant in stages, from silent testing to advanced mode.
</Card>


## Related topics

- [Customer Value Messaging for AI-Powered Support](/get-started/talking-to-customers-about-ai-powered-support-thread-customer-value-messaging.md)
- [Create your first Voice AI agent](/ai-agents/voice-ai-setup-phase-1-initial-configuration.md)
- [The AI-service pitch](/start-here/roles/sales-business-development/the-ai-service-pitch.md)