By default, form submissions in HubSpot require a populated email address field to create contacts. However, you can allow visitors to submit a form without providing their email address and still be added to your database.
In your HubSpot account, click the settings iconsettings in the main navigation bar.
In the left sidebar menu, navigate to Marketing > Forms.
Click the Submission Settings tab.
Click to toggle the Allow submissions without email addressesto create contacts switch on.
If this setting is disabled and you create a form without an email address, you will see a prompt to add the email field to your form to allow submissions without email addresses to create contacts.
Contacts created via form submissions without an email address will deduplicate based on cookies. If two people with the same cookie fill out a form with no email address (e.g., if they were using the same device), both submissions will be associated with the same contact record. However, if the Always create contact for new email address option is enabled, each submission will create a new contact.
If you're using a custom email field and have this setting enabled, form submissions will create contacts. However, because the default HubSpot Email property has no value, these contacts cannot be emailed or be enrolled in workflows.