Same pdf needs to be signed and saved as customers name.

I have an agreement that needs to be signed by each customer, and then saved under their name. Sounds simple enough, but once they sign the document and I save it, the original document remains signed and is no longer "blank" for the next customer to sign (and save again under a different name). I'm sure it's simple, but I'm not getting it. And yes, I'm using the subscription based service. Thank you in advance.