How to Amend a Tax Return

Kiplinger for Daily Finance writes:  Q: When I was doing my 2012 tax return this year, I realized that I could have claimed the child-care credit for my son's summer camp expenses in 2011, but I didn't know I qualified then. Is it too late to get the money?

Answer: It's not too late. You have up to three years after the due date of your return to file an amended return and claim the credit. The child-care credit is a frequently overlooked tax break for people who have kids under age 13 and pay for child care so they can work or look for work. The cost of a nanny, babysitter, day care, preschool, before-school and after-school care, and day camp during summer and school vacations can all count. The credit can be worth up to $600 to $1,050 if you have one child, or $1,200 to $2,100 if you have two or more children. The lower your income, the larger the credit, but many people don't realize that there's no income cutoff to qualify. See Take a Tax Break for Summer Camp for details.

File an amended return by submitting Form 1040X. You don't need to refile your whole return you just need to mark the year of the return you're amending at the top of the form, note the changes you're making, and include revised copies of any supplemental forms that are affected (such as Form 2441 for the child-care credit, or Schedule A for changes to itemized deductions see IRS.gov for the forms). If the change lowers your tax liability, the IRS will send you a refund, complete with interest (the current rate is 3%) back to the original due date of the return. It usually takes up to 12 weeks for the IRS to process amended returns.

See the Instructions for Form 1040X and the IRS's amended return page for more information. You can check on the status of your amended return after you file using the Where's My Amended Return? tool starting three weeks after you file your amended return.

Reducing your federal income tax could also lower your state income tax liability. File your amended return first, then get a copy of the transcript of your account from the IRS (confirming that you amended your federal return) and file an amended state return, with a copy of your Form 1040X.