Intellectual Property Assignment

By default the freelancer does. Absent a signed assignment, a contractor typically owns the copyright in what they create and the client holds only an implied licence to use it for the purpose it was commissioned for. That is why agencies, designers, and developers should sign an IP assignment alongside the services contract rather than relying on the invoice.

An assignment transfers ownership, so the assignor keeps nothing and cannot use the property afterwards unless the agreement grants it back. A licence leaves ownership where it is and grants defined permission to use the property, which can be limited by territory, field, or time. If you want the other side to have no residual claim, use an assignment.

For copyright, yes — transfers of ownership generally must be in a signed writing to be effective, which is why oral agreements about code and artwork fail so often. Patent and trademark assignments should also be written, and recording them with the patent and trademark office protects against later conflicting claims. Quill's assignment includes further-assurances language so the assignor must sign recordation paperwork if it is needed.