> For the complete documentation index, see [llms.txt](https://docs.senpiper.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.senpiper.com/general-system-settings/enable-sign-up/build-a-sign-up-form.md). # Build a Sign-up form System Admin can add fields to the sign-up form builder by dragging & dropping them on the workspace. The drag & drop functionality works similarly to [**adding a field to the form builder**](/form-builder/creating-forms/adding-fields-and-saving-a-form.md). Also, system admins can add only the [**basic fields**](/form-builder/creating-forms/adding-fields-and-saving-a-form/building-forms.md#basic-fields) on the sign-up form.

{% hint style="info" %} 'Name', 'Email' & 'Phone number' fields for a sign-up form are mandatory and are pre-added. Users may not be able to delete the same but can modify a few settings. {% endhint %} ### 1. Email Field The System Admin can modify the settings for the pre-added email field in the sign-up form builder.

### 2. Phone Number Field The System Admin can modify the settings for the pre-added phone number field in the sign-up form builder.

Phone Number Setting for Pre-added field

{% hint style="warning" %} System Admin won't be able to add [**Section Field**](/form-builder/creating-forms/adding-fields-and-saving-a-form/individual-field-settings.md#section) to the sign-up form builder {% endhint %}