Can form users upload attachments to the forms?

Hi!

Can customers who  the forms are being sent to upload attachments to the forms?

Yes, your users can upload files to your form. Inside of this guide you can find how to create file upload form:

How to Create File Upload Forms

You can also check this guide to see how to change and increase the file upload size limit:

Changing the File Upload Size Limit

Hope this will help. Let us know if you need further assistance.