Knowledgebase
How to add fields to the user registration form in Drupal
In Drupal you can include additional fields on the user registration form, and if you want to, you can also make these fields required. To do this, log in to the admin panel of your Drupal, click on the Configuration tab in the top navigation bar, and on the page that opens click on Account settings. At the top right corner of the panel that is displayed there are a few sub-tabs; click on the Manage Fields sub-tab. On the page that is shown there's a table with the existing fields. These fields can be included on the user account page, or they can also be included on the registration form. If you want to add an existing field to the registration form, click on its edit button in the table (the preconfigured User name and password and Timezone fields cannot be edited).
When you click on the edit button this will display the page with the general settings for the particular field (the Edit sub-tab page). On that page there's a checkbox labeled Display on user registration form. Mark that checkbox to add the field to the registration form. Just above that checkbox there's another one labeled Required field. Mark that checkbox as well, if you want to make the field required. Then click on the Save settings button at the bottom of the page to save the changes.
You can, of course, add a new field and then include it on the registration form. To do this, on the Manage Fields sub-tab page for the account settings type the name of the field in the text area under Add new field, select the field type and the widget from the respective drop-down menus and click on the Save button. This will automatically display the field settings of the field type that you chose. When you configure them and you click on the Save field settings button, the general settings will be displayed (you can navigate between the two pages by using the sub-tabs at the top right corner of the panel). This is the page which we already discussed, and on which you'll find the settings for adding the field to the registration form and making it required. For more information on how to add new fields you can also check out the tutorial on managing fields in Drupal.