The New York Amended Certificate of Doing Business Under an Assumed Name (.pdf) is a document filed with the New York Department of State that provides legally recognized evidence that your business is doing business under an assumed name. It is required when a business entity wants to register a DBA (Doing Business As) name in New York. The Amended Certificate must include the original business name, the new assumed name, and the county where the business is located. The two types of New York Amended Certificate of Doing Business Under an Assumed Name (.pdf) are: 1. New York Certificate of Amendment to Assumed Name: This is for businesses that need to change the assumed name they have already registered. 2. New York Certificate of Merger to Assumed Name: This is for businesses that need to combine two or more assumed names into one.