A New York Amendment of an Assumed Name Certificate is a document filed with the New York Department of State to legally change a business name in the state. This document must be filed when a business has changed its name from one that is already registered with the Department of State. There are two types of New York Amendment of an Assumed Name Certificate: 1) An Unincorporated Business Amendment of an Assumed Name Certificate: This document must be filed when an unincorporated business has changed its assumed name. The document must include the original assumed name, the new assumed name, and the signature of the owner(s) of the business. 2) A Corporation Amendment of an Assumed Name Certificate: This document must be filed when a corporation has changed its assumed name. The document must include the original assumed name, the new assumed name, and the signature of the corporate officer who is authorized to sign on behalf of the corporation. Both of this Amendment of an Assumed Name Certificate documents must be filed with the New York Department of State and the appropriate filing fee must be paid. Once the filing has been accepted, the Department of State will issue a Certificate of Amendment, which is evidence that the change of assumed name has been registered with the state.