1. Incorrect amount of tax entered from the tax table. Find your correct filing status at the top of the tax table and copy the correct amount from that column onto your return.
2. Error in computing the credit for child- and dependent-care expenses. Carefully work through Form 2441 and the accompanying worksheet contained in the instructions. The child-care credit could be limited if you are subject to the Alternative Minimum Tax. The worksheet will help you figure out if the limit applies.
3. Not claiming the earned income credit. Low-income taxpayers may be entitled to a credit. To see if you qualify, use the earned income-credit worksheet contained in the instructions for filing your tax return.
4. Income tax withholding and estimated tax payments entered on the wrong line. Federal income tax withheld is reported on one line. Estimated tax payments go on the next line.
5. Wrong Social Security number. If you use the IRS peel-off mailing label, check to make sure your number is correct. And…double-check your Social Security number on your W-2.
6. Indicating overpayment to be credited to estimated tax…when you actually want a refund. Be sure to mark the correct line.
7. Adding income, deductions, or credits incorrectly. Double-check the arithmetic for all these amounts before filing your return.
8. Entering Social Security tax withheld instead of federal withholding tax. Copy the amount of federal tax withheld from Box 9 of your W-2.
9. Incorrect computation of refund or balance due.
10. Computation error when figuring medical and dental expenses. You must figure your Adjusted Gross Income before you can calculate the deduction for medical and dental expenses. Read the instructions carefully for the rules of how to do this.