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## title: Phone numbers

Phone numbers are the most common inbound entrypoint for Voice AI.

## Setup flow

1. Add or port a number to Voximplant.
2. Attach the number to your application.
3. Create an inbound routing rule that matches the number.
4. Attach your inbound Voice AI scenario as the first scenario in that rule.

## Routing pattern tips

* Use exact or constrained regex patterns for production numbers.
* Put country- or campaign-specific rules above a global fallback (`.*`).
* Use the rule checker before testing live calls.

## Voice AI notes

* Use one scenario and branch by destination when needed (`event.destination`).
* Keep prompts and responses telephony-friendly.
* For multi-region deployments, use separate rules per number group and route to language-specific scenarios.

## Common issues

* Number is attached to a different application than the routing rule.
* Rule order is wrong, so a broader rule captures traffic first.
* No outbound caller ID is configured for transfer tool paths that place PSTN calls.

## Links

* Phone numbers basics: [https://voximplant.com/docs/getting-started/basic-concepts/phone-numbers](https://voximplant.com/docs/getting-started/basic-concepts/phone-numbers)
* Routing rules: [https://voximplant.com/docs/getting-started/basic-concepts/routing-rules](https://voximplant.com/docs/getting-started/basic-concepts/routing-rules)

<Info title="Screenshots needed">
  - Number attached to application in Control Panel.
  - Routing rule pattern for a specific number and successful rule-checker result.
</Info>