New York Application For Index Number is an official form from the New York State Department of Taxation and Finance which is used to register a business for an index number. This form is required by the Department of Taxation and Finance for any business that is engaged in certain activities in New York State, such as sales and use tax, withholding tax, corporate franchise tax, and personal income tax. There are three different types of New York Application For Index Number forms including: 1) Sales Tax Vendor Registration Application, 2) Withholding Tax Registration Application, and 3) Business Registration Application. Each of these forms requires information about the business, such as the name, address, contact information, and federal tax identification number. The completed forms must be submitted to the Department of Taxation and Finance in order to obtain the index number.