Five Common Tax Mistakes to Avoid

The 2010 tax filing deadline is looming; the last day to file your tax return-without an extension — is Monday, April 18th.

If you haven't already completed yours, here arefive simple tips in mind before you hit the send button or drop the envelope in the mail:

1. Sign your tax return: Make certain that you-and your spouse, if applicable-sign and date your tax return! If you fail to sign and date your return, the Internal Revenue Service will consider it as if you didn't file at all. You can expose yourself to penalties and hassles that are avoidable. 
2. Don't forget to include payment: You owe, you owe, but you forgot to pay. Don't be saddled with penalties! Enclose your checkwith your return, and indicate the tax year and social security number on the check. 
3. Double, no, triple-check those math calculations: If you have math angst-and even if you don't-be sure to double check your work. No, make that triple-check your work! It's easy to make an error, but don't do it. Use a calculator or let your significant other check your work. It's better than having the IRS find the error and adjusting your return for you. 
4. Include your correct Social Security Number on your tax form: Your tax return will be rejected, plain and simple. And while rejection is usually not a good thing, it's even less of a good thing when it involves the IRS. Make sure that your social security number is correctly indicated on your tax return.
5. Include all credits and deductions: It's likely that if you want to make a donation, it won't be to the IRS. This year, as in previous years, the IRS will collect millions and millions of dollars of overpaid taxes, due to overlooking a deduction here and there. Pay attention to all of the potential credits and deductions for which you are eligible.

The IRS is also warning taxpayers of the most common tax scams or frauds in 2011 by highlighting them as group it's taken to calling the "Dirty Dozen" (see the attached video).

“The Dirty Dozen represents the worst of the worst tax scams,” IRS Commissioner Doug Shulman said. “Don’t fall prey to these tax scams. They may look tempting, but these fraudulent deals end up hurting people who participate in them.”

If you've filed your return already; congratulations. If not, make sure you sign and date your return; include payment with your return; double check your calculations; make sure that your correct social security number is indicated and you have taken all of the credits and deductions available to you. Then, send off your return knowing you paid attention to the details, and celebrate! 

Editor's Note: Lori Brillhart is a business columnist for Mercer Island Patch.