The assignment of a contract occurs when one party to the contract (the assignor) transfers its rights and responsibilities under the contract to another person or entity (the assignee)—usually someone who was not a party to the original contract.

Contracts often include a paragraph or clause near the end of the agreement that addresses whether the parties may assign the contract.

In Illinois, the assignment of a contract is generally permissible unless the contract itself prohibits it or if the assignment would significantly change the obligations of the other party. Illinois follows the common law principle that contractual rights can be assigned unless the assignment would materially alter the duties of the obligor, increase the obligor's burden, or impair the chance of obtaining performance. A contract may include a specific clause that either allows for assignment with certain stipulations or outright prohibits it. If such a clause is present, its terms will dictate the ability to assign the contract. When a contract is silent on the issue of assignment, it is typically assumed that assignment is allowed. However, certain types of contracts, such as personal service contracts or contracts with a highly personal nature, are generally considered non-assignable due to the personal skills or qualities involved. It is advisable to consult with an attorney to understand the specific implications of assigning a contract in Illinois, as the enforceability of an assignment clause and the legal consequences of an assignment can vary based on the contract's content and the context of the assignment.