If, after filing your income tax return, you receive an additional tax statement or discover that an error was made, do not submit a second tax return.
If corrections are necessary, you must file Form CA-6, Application for Abatement/Amended Return. You may have one mailed to you by calling (617) 887-MDOR or toll-free in Massachusetts, 1-800-392-6089.
Mail Claims to:
Massachusetts Department of Revenue Customer Service Bureau, PO Box 7031 Boston, MA 02204
You can also file it on the MA website by clicking on the following link. Individual Income Tax Web Abatement