Tax laws do not always give taxpayers enough time to discover a mistake. An original return has its due date, a belated return has a limited window, and a revised return, too, has a prescribed deadline. What if an asses see discovers an omission or incorrect claim only after these windows have closed? The updated return provides that second chance. An updated return allows a taxpayer, whether or not an earlier return was filed, to voluntarily disclose in advertently omitted income or correct other omissions within 48 months from the end of the relevant assessment year, subject to certain restrictions.