Collect user attributes during sign-up

User attributes collected during sign-up are stored with the user's profile in your directory. You can choose from built-in attributes or create custom ones in the user flow settings.

• Built-in user attributes. Microsoft Entra External ID has built-in user attributes that can be collected during sign-up, including:

  • City
  • Country/Region
  • Display Name
  • Email Address
  • Given Name
  • Job Title
  • Postal Code
  • State/Province
  • Street Address
  • Surname

• Custom user attributes. You can also create custom user attributes to collect additional information during sign-up using the following input types:

  • String text box
  • Radio buttons
  • Multiselect checkboxes
  • Numeric text box
  • Single-select checkbox

Checkboxes and radio buttons can include hyperlinks to other content, such as terms of use and privacy policies. The following example shows a sign-up page that combines built-in attributes and custom attributes:

In this example:

• The Display Name field is a built-in attribute.
• The Loyalty Number is a custom attribute with a free-form entry field that accepts a numeric integer. You can configure this format using the Int data type and NumericTextBox user input type.
• The terms of use and privacy policy custom attributes are separate, single-select checkboxes with labels containing hyperlinks. You can configure a single checkbox using the Boolean data type, which defaults to the CheckboxSingleSelect user input type. Use Markdown language to add hyperlinks to the checkbox label.

Other input types are available, including multiselect checkboxes, radio buttons, and free-form text entry fields. Learn how to create custom user attributes in this article.

Where custom user attributes are stored

Custom user attributes are also known as directory extension attributes because they extend the user profile information stored in your directory. All extension attributes for your customer tenant are stored in an app named b2c-extensions-app. After a user enters a value for the custom attribute during sign-up, it's added to the user object and can be called via the Microsoft Graph API using the naming convention extension_<b2c-extensions-app-id>_attributename.

If your application relies on certain built-in or custom user attributes, you can also include these attributes in the token that is sent to your application.

Referencing custom user attributes

The custom user attributes you create are added to the b2c-extensions-app registered in your customer tenant. If you want to call a custom attribute from an application or manage it via Microsoft Graph, use the naming convention extension_<b2c-extensions-app-id>_<custom-attribute-name> where:

• <b2c-extensions-app-id> is the b2c-extensions-app application ID with no hyphens.
• <custom-attribute-name> is the name you assigned to the custom attribute.

To find the application ID for the b2c-extensions-app registered in your customer tenant:

1. Sign in to the Microsoft Entra admin center.
2. Browse to Identity > App registrations > All applications.
3. Select the application b2c-extensions-app. Do not modify. Used by AADB2C for storing user data.
4. On the Overview page, use the Application (client) ID value, for example: 12345678-abcd-1234-1234-ab123456789, but remove the hyphens.

Example: If you created a custom attribute named loyaltyNumber, refer to it as follows:

extension_12345678abcd12341234ab123456789_loyaltyNumber

Create custom user attributes

Before you begin, determine the best way to gather user input for each custom attribute you want to collect. Refer to the following table to find the appropriate data types and user input types.

Custom user attribute data and input types

Data type	User input type	Description
String	TextBox	Free-form text entry field.
String	RadioSingleSelect	Series of radio buttons with only one selection allowed. The Text for individual radio buttons can include hyperlinks formatted in Markdown language.
String	CheckboxMultiSelect	Series of one or more checkboxes with multiple selections allowed. The Text for individual checkboxes can include hyperlinks formatted in Markdown language.
Boolean	CheckboxSingleSelect	Single boolean checkbox with a label. The Label for the checkbox can include hyperlinks formatted in Markdown language.
Int	NumericTextBox	Free-form integer entry.

To define a custom user attribute, you first create the attribute at the tenant level so it can be used in any user flow in the tenant. Then you assign the attribute to your sign-up user flow and configure how you want it to appear on the sign-up page.

To create a custom user attribute

1. Sign in to the Microsoft Entra admin center.

2. If you have access to multiple tenants, use the Settings icon in the top menu to switch to your customer tenant from the Directories + subscriptions menu.

3. Browse to Identity > External Identities > Overview.

4. Select Custom user attributes. The list contains all user attributes available in the tenant, including any custom user attributes that have been created. The Attribute type column indicates whether an attribute is built-in or custom.

5. Select Add. In the Add an attribute pane, enter a Name for the custom attribute (for example, "Terms of use").

6. In Data Type, choose String, Boolean, or Int depending on the type of data and user input control you want to create. String attributes have a default user input type value of TextBox, but you'll be able to change this in a later step (for example if you want to configure radio buttons or multiselect checkboxes).

7. (Optional) In Description, enter a description of the custom attribute for internal use. This description isn't visible to the user.

   

8. Select Create. The custom attribute is now available in the list of user attributes and can be added to your user flows.

Include the custom user attribute in a sign-up flow

Follow these steps to add custom user attributes to a user flow you've already created. (If you need to create a new user flow, see Create a sign-up and sign-in user flow for customers.)

1. Sign in to the Microsoft Entra admin center.

2. If you have access to multiple tenants, use the Settings icon in the top menu to switch to your customer tenant from the Directories + subscriptions menu.

3. Browse to Identity > External Identities > User flows.

4. Select the user flow from the list.

5. Select User attributes. The list includes any custom user attributes you defined as described in the previous section. For example, the new Terms of use attribute now appears in the list. Choose all the attributes you want to collect from the user during sign-up.

   

6. Select Save.

Configure the user input types and page layout

On the Page layout page, you can indicate which attributes are required and arrange the display order. You can also edit attribute labels, create radio buttons or checkboxes, and add hyperlinks to more content (such as terms of use or a privacy policy).

1. Sign in to the Microsoft Entra admin center.

2. Browse to Identity > External Identities > User flows.

3. From the list, select your user flow.

4. Under Customize, select Page layouts. The attributes you chose to collect appear.

5. Edit the label for any attribute by selecting the value in the Label column and modifying the text.

6. Configure checkboxes or radio buttons:

   • Single-select checkbox: A Boolean attribute type renders as a single-select checkbox on the sign-up page. To configure the text that displays next to the checkbox, select and edit the value in the Label column. Use Markdown language to add hyperlinks. For details, see To configure a single-select checkbox (CheckboxSingleSelect)
   • Multiselect checkboxes: Find the String data type attribute you want to configure, and select the value in the User Input Type column to open the editor pane. Choose the CheckboxMultiSelect user input type and enter the values. For details, see To configure multiselect checkboxes (CheckboxMultiSelect).
   • Radio buttons: Find the String data type attribute you want to configure, and select the value in the User Input Type column to open the editor pane. Choose the RadioSingleSelect user input type and enter the values. For details, see To configure radio buttons (RadioSingleSelect)

7. Change the order of display by selecting an attribute and choosing Move up, Move down, Move to top, or Move to bottom.

8. Make an attribute required by selecting the checkbox in the Required column. All attributes can be marked as required. For multiselect checkboxes, "Required" means that the user must select at least one checkbox.

9. When all your changes are complete, select Save.

To configure a single-select checkbox (CheckboxSingleSelect)

An attribute with a Boolean data type has a user input type of CheckboxSingleSelect. You can modify the text that displays next to the checkbox and include hyperlinks.

1. On the Page layouts page, find the attribute with data type of Boolean that you want to configure.

2. Select the value in the Label column and enter the text you want to display next to the checkbox. Use Markdown language to add hyperlinks. For example:

   • To configure the label for a Terms of use attribute, you could enter:

     I have read and agree to the [terms of use](https://woodgrove.com/terms-of-use).

   • Or, you could combine your terms of use and privacy policy into a single required checkbox:

     I have read and agree to the [terms of use](https://woodgrove.com/terms-of-use) and the [privacy policy](https://woodgrove.com/privacy).

3. Select Ok.

   

4. On the Page layouts page, select Save.

To configure multiselect checkboxes (CheckboxMultiSelect)

An attribute with a String data type can be configured as a CheckboxMultiSelect user input type, which is a series of one or more checkboxes that appear under the attribute label. The user can select one or more checkboxes. You can define the text for individual checkboxes and include hyperlinks to other content. Making this attribute "Required" means that the user must select at least one of the checkboxes.

1. On the Page layouts page, find the attribute with data type of String that you want to configure as a series of checkboxes.

2. Select the value in the Label column and enter the heading you want to display above the series of checkboxes, for example How did you hear about us?.

3. Select the value in the User Input Type column to open the editor pane.

4. In the editor pane, under User input type, select CheckboxMultiSelect.

5. For each checkbox you want to add, start on a new line and enter the following information:

   • Under Text, enter the text you want to display next to the checkbox. Use Markdown language to add hyperlinks.

   • Under Values, enter a value to be written on the user object and returned as the claim if the user selects the checkbox.

6. Select Ok.

   

7. On the Page layouts page, select Save.

To configure radio buttons (RadioSingleSelect)

An attribute with a String data type can be configured as a RadioSingleSelect user input type, which is a series of radio buttons that appear under the attribute label. The user can select only one radio button. You can define the text for individual radio buttons and include hyperlinks to other content.

1. On the Page layouts page, find the attribute with data type of String that you want to configure as a radio button or series of radio buttons.

2. Select the value in the Label column and enter the heading you want to display above the series of radio buttons, for example Sweatshirt size.

3. Select the value in the User Input Type column to open the editor pane.

4. In the editor pane, under User input type, select RadioSingleSelect.

5. For each radio button you want to add, start on a new line and enter the following information:

   • Under Text, enter the text you want to display next to the radio button. Use Markdown language to add hyperlinks.

   • Under Values, enter a value to be written on the user object and returned as the claim if the user selects the radio button.

6. Select Ok.

   

7. On the Page layouts page, select Save.

Next steps

Add attributes to the ID token returned to your application

Learn more about creating a sign-up and sign-in user flow for customers