Your signers never have to sign up for a HelloSign account in order to complete a signature request. Once they sign the document, we'll email the finalized PDF to all of the signers, and give them the option of creating a password to access the document on HelloSign if they choose. Creating a password is completely optional!
We do not market or advertise to your clients in any way unless they choose to create a password and create a HelloSign account of their own.
Why is my client being asked to sign in?
Your client most likely signed a document via HelloSign in the past, and created a password. If your client doesn't recall doing this, he/she should create a new password.