Can clients upload an attachment (PDF for example as needed is a verification letter) to my form?

Is there a way to upload a verification letter to a JofForm registration form?

Yes, you just need to add a File Upload field in your form. Here's how:

1. In Form Builder V4, click the "Add Form Element" button.

2. Under the "Basic" tab, look for "File Upload" tool. Drag it to the form.

Please check these guides:
-How-to-Create-File-Upload-Forms
-How-to-Change-the-Allowed-File-Types-Extensions-in-the-Upload-Field
-Changing-the-File-Upload-Size-Limit

Hope that helps. Thank you.

Thank you!