# createPhoneNumber()

Creates a [PhoneNumber](https://clerk.com/docs/reference/types/phone-number.md) for the specified user.

```ts
function createPhoneNumber(params: CreatePhoneNumberParams): Promise<PhoneNumber>
```

## `CreatePhoneNumberParams`

| Name                    | Type    | Description                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
| ----------------------- | ------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| userId                  | string  | The ID of the user to create the phone number for.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| phoneNumber             | string  | The phone number to assign to the specified user. Must adhere to the E.164 format standard for phone number format.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| primary?                | boolean | Whether or not to set the phone number as the user's primary phone number. Defaults to false, unless it is the first phone number.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
| verified?               | boolean | Whether or not the phone number is verified.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
| reservedForSecondFactor | boolean | Whether or not the phone number is reserved for multi-factor authentication. The phone number must also be verified. If there are no other reserved second factorsSecond factor verification, also known as two-factor authentication (2FA) or multi-factor authentication (MFA), is the process of verifying a user's identity using an additional factor. For example, if a user signs in with their email and password, and then, is asked to also provide an OTPA one-time password (OTP) is a code that is used to authenticate a user. The OTP is typically sent to a user's email address or phone number and must be entered within a certain time period to be valid. sent to their phone number, the OTP is the second factorA second factor is an additional factor of authentication that is required to complete the authentication process. For example, if a user signs in with their email and password, and then is asked to also provide an OTPA one-time password (OTP) is a code that is used to authenticate a user. The OTP is typically sent to a user's email address or phone number and must be entered within a certain time period to be valid. sent to their email in order to verify their identity, the email OTP is the second factor.., the phone number will be set as the default second factor. |

## Example

> Using `clerkClient` varies based on the SDK you're using. Refer to the [overview](https://clerk.com/docs/reference/backend/overview.md) for usage details, including guidance on [how to access the `userId` and other properties](https://clerk.com/docs/reference/backend/overview.md#example-get-the-user-id-and-other-properties).

```tsx
const response = await clerkClient.phoneNumbers.createPhoneNumber({
  userId: 'user_123',
  phoneNumber: '15551234567',
  primary: true,
  verified: true,
})
```

## Backend API (BAPI) endpoint

This method in the SDK is a wrapper around the BAPI endpoint `POST/phone_numbers`. See the [BAPI reference](https://clerk.com/docs/reference/backend-api/tag/phone-numbers/POST/phone_numbers){{ target: '_blank' }} for more information.

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## Sitemap

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