Passing a Redirect URL to an Account Engagement Form as a Hidden Field

1. Create a custom field to store your redirect URL and set type to Hidden. Make sure this field is NOT set to record and display multiple responses, as this will cause an error in the redirect. Note the field's ID.
2. Edit your form. On Step 2 of the form wizard, add your hidden field. Go to the Advanced section and mark Always display even if previously completed. Save the field.
3. In Step 4 of the form editor, add the redirect URL script to your form’s Thank You Code. Replace the two “field_id” references in the script with the ID of the custom field you created in the first step. Save Form.
4. In your iframe code on your site, update the src attribute and append ?field_id=redirect_url, where field_id is your custom field’s ID and redirect_url is the location that you want to send the prospect to upon completion. For example: 

<iframe style=“border: 0;” src=“https://your.trackerdomain.com/form/url/12345/abcde?url_redirect_destination=www.pardot.com”” width=“100%” height=“500” frameborder=“0”></iframe>