Use Form 1065-X, if you are not filing electronically, to: Correct items on a previously filed Form 1065, Form 1065-B, or Form 1066. Make an Administrative Adjustment Request (AAR) for a previously filed Form 1065, Form 1065-B, or Form 1066. Current Revision Form 1065-X PDF Instructions for Form 1065-X (Print Version PDF) Recent Developments Clarifications for Instructions for Form 1065-X, Amended Return or Administrative Adjustment Request (AAR) -- 19-MAR-2020 Other Items You May Find Useful All Form 1065-X Revisions Other Current Products Related About Form 1065, U.S. Return of Partnership Income About Form 1066, U.S. Real Estate Mortgage Investment Conduit (REMIC) Income Tax Return