Adding custom fields to an affiliate sign up form is a great way to collect additional data from your affiliates. There are endless use cases for this, such as collecting social media usernames or asking affiliates where they plan on promoting.

To set this up, first go to the Creatives tab in your dashboard and click on the "Sign up forms" page.

Click on the form you wish to add fields to, or create a new form. From within the form editor, head to the Fields tab and click "+ New Field" to create a new custom field.

You'll be given the option to create a text field or a numerical field. Text fields can accept any response while numerical fields can only accept number responses.

Next, you'll be prompted to give the field a name. This is for your internal use only, you'll be able to customize the label text of the field on the form later. You can also make the field required or optional.

Once you click Create, you'll see a new field appear in the editor, as well as in the actual form itself.

To customize the label text that appears in the form, go to the Text tab in the editor, and then navigate to the Labels subtab.

When an affiliate submits a custom field response, you'll be able to view that data in their affiliate profile page.