New York State Department of Taxation and Finance Customer FAQ

If you made a mistake on your IT-201, you can correct it by filing an amended return. Use Form IT-201-X, Amended Resident Income Tax Return, for this purpose. However, if the mistake was in the Department's favor, they will likely correct it for you. If the department disagrees with the changes or questions your calculations, they will contact you for provided proofs or explanations. It's important to check your figures and keep any related work papers till the department confirms that changes are correct. Please ensure to provide a detailed explanation of the changes on the Form IT-201-X.