Your Money: Amending your tax return Form 1040-X

Fix tax-filing mistakes with form l040X (Amended US Individual Income Tax Return]. The simple form allows you to correct a mistake going back up to three tax years. It asks how much adjusted gross income you reported before ... what you are now reporting... and how much the number has changed. But many tax breaks relate to income and are not allowed at certain income levels, so filing a l040X may invalidate some parts of your original 1040 or make you ineligible for deductions that you could previously claim. What to do: If your return is complex or if there is any doubt, it may be better to redo your entire form 1040, adjusting all calculations that could give or take away deductions based on income, and include this with your 1040X, even though the IRS does not require you to do that.