# Phone Validation Guide Via OTP

> **In simple terms:** This guide shows you how to verify that a phone number belongs to your user. Truora sends a one-time code via SMS, phone call, or WhatsApp, and the user enters it to confirm they own the number.

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The Phone Validator is used to validate if the phone number registered in the flow (or Chatbot) belongs to the end-user. This is done by sending an OTP (One-Time Password) code that the user must return as a response.

The OTP code can be delivered as a **Text message** (SMS), **Phone call** or through **Whatsapp**. You can set the number of allowed retries for this validation, with a maximum value of 3.

- **NOTE:** If you set ``Whatsapp`` as the OTP delivery method, you must have your own **WABA line** and **Activate** it. Then, create your **Outbound message** of type **OTP** and **Contact Support** to provide your **Outbound ID** for inclusion in your process:
  - This guide explains how to {{< newtab href="/guides/waba_acquisition/" >}}Create a WABA line and Activate it{{< /newtab >}}.
  - This guide explains how to {{< newtab href="/guides/outbound/" >}}Create an Outbound message{{< /newtab >}} and obtain your message's **Outbound ID**. Follow the guide and select **OTP** in the **Message Category**.
    - After the message is approved, **Contact Support** and provide the **Outbound ID** of your message to our team to include it in your process.

{{<img width="100%" src="/images/illustrations/phone_and_email_validation/phone_validation.gif" alt="phone">}}

For information on API usage, please refer to {{< newtab href="/guides/phone_validation_api/" >}}Phone Validation via API{{< /newtab >}}.

* Additionally, using our API you can configure other parameters to improve the behavior of the validators and the user experience according to your particular needs. Please see the {{< newtab href="/guides/config_validators/" >}}Config Validator Guide{{< /newtab >}} for more information on customization.

> **Please Note:**
> - The config parameters you will see in the {{< newtab href="/guides/config_validators/" >}}Config Validator Guide{{< /newtab >}} are global parameters for your account and will affect all the validations across your account.
> - However, validations performed using the flow you created will prioritize the configuration in the Validator Block of your flow. All other parameters, not configurable within the Flow Builder, will take the global configuration values.

* Remember also you can customize your web flow. For more information please visit [Customize Web Flow](/guides/customize_web_flow) guide.

## Integrating Your Flow
Once you have [created and tested the Flow](/guides/flows_web#Testing_The_Flow_Template), you need to integrate it. Please check out the following guide for more information: [How to create a Web Integration Token](/guides/web_integration_token/)

## Receiving Results from the Flow
The information about the results of the validations made to the user can be notified through [Webhooks](/guides/webhook_rule/). This alternative allows you to receive hooks of the 
actions/rules created.

For information about how to integrate this validator in WhatsApp, visit [**Here**](/guides/how_use_whatsapp_kyc/#phone-and-email).