Tax filing mistakes and how to avoid them

For the millions of taxpayers who will file in the last two weeks before deadline, the IRS offers the following reminders to avoid tax filing mistakes:

File electronically. Filing electronically, whether through e-file or IRS Free File, vastly reduces tax return errors, as the tax software does the calculations, flags common errors and prompts taxpayers for missing information. And best of all, there is a free option for everyone.
Mail a paper return to the right address. Paper filers should check IRS.gov or their form instructions for the appropriate address where to file to avoid processing delays.
Take a close look at the tax tables. When figuring tax using the tax tables, taxpayers should be sure to use the correct column for the filing status claimed.
Fill in all requested information clearly. When entering information on the tax return, including Social Security numbers, take the time to be sure it is correct and easy to read. Also, check only one filing status and the appropriate exemption boxes.
Review all figures. While software catches and prevents many errors on e-file returns, math errors remain common on paper returns.
Get the right routing and account numbers. Requesting direct deposit of a federal refund into one, two or even three accounts is convenient and allows the taxpayer access to his or her money faster. Make sure the financial institution routing and account numbers entered on the return are accurate. Incorrect numbers can cause a refund to be delayed or deposited into the wrong account.
Sign and date the return. If filing a joint return, both spouses must sign and date the return. E-filers can sign using a self-selected personal identification number (PIN).
Attach all required forms. Paper filers need to attach W-2s and other forms that reflect tax withholding, to the front of their returns. If requesting a payment agreement with the IRS, also attachForm 9465 to the front of the return. Attach all other necessary schedules and forms in the sequence number order shown in the upper right-hand corner.
Keep a copy of the return. Once ready to be filed, taxpayers should make a copy of their signed return and all schedules for their records.
Request a Filing Extension. For taxpayers who cannot meet the April 15 deadline, requesting a filing extension is easy and will prevent late filing penalties. Either use Free File  or Form 4868. But keep in mind that while an extension grants additional time to file, tax payments are still due April 15.
Owe tax? If so, a number of e-payment options are available. Or send a check or money order payable to the “United States Treasury.”
Taxpayers may find additional help and resources on IRS.gov, including the IRS Services Guide.