Below is a list of common sections included in Assignment And Assumption Agreements. These sections are linked to the below sample agreement for you to explore.An assignment and assumption of lease is a legal real estate document that allows one party to transfer rights and obligations of a lease to another party. (f) An Assignment and Assumption of Water Contracts in the form of. Filed with the Securities and Exchange Commission. Once you go into a purchase and sale agreement with your seller you need an assignment agreement to assign that to your end buyer.