What's the Difference Between an Amended Return and a Superseded Return?

If you need to fix a mistake on your tax return, whether you file an amended return or a superseded return depends on whether the original filing deadline has passed. A superseded return is a corrected return filed before the original due date — including any extensions — and it completely replaces the original return as if the first one was never filed. An amended return is filed after the original due date using Form 1040-X, and it officially corrects a previously filed return. The practical difference is that a superseded return is simpler and leaves a cleaner record, while an amended return creates a paper trail showing what changed. If you discover an error shortly after filing but before the deadline, it's generally better to file a superseded return; after the deadline, you'll need to go the amended return route.