9 Common and Costly Tax Mistakes

Don’t let haste make waste — especially when it comes to your income taxes.

Making mistakes on your tax return can cost you time, money or both. In some cases, such mistakes can cause your return to be rejected by the IRS or lead to an audit, which could cost you even more time and money.

So here’s a look at some of the most common tax-time screw-ups.

Mistake No. 1: Paying for tax preparation when you can get it free

Would you pay a couple hundred bucks for something you can get for free? Millions of Americans do it every year.

Companies such as TurboTax, H&R Block and Tax Slayer offer free tax software. Also, depending on your income level, you may qualify for any number of free services. For more, check out “7 Ways to Get Your Taxes Done for Free.”

Mistake No. 2: Getting your Social Security numbers wrong

On its list of common tax mistakes, the IRS puts incorrect and missing Social Security numbers at the top.

Long gone are the days in which you could claim dependents without a Social Security number. Today, every member of your household listed on your return needs to have one of these numbers.

Make sure to double-check all of the numbers before submitting your return to ensure there aren’t any transposed or missing digits.

Mistake No. 3: Spelling your name wrong

Sure, you know what your name is. But maybe you’re typing too quickly and hit the wrong key. Or you might be interrupted while filling out the form and start up again later at the wrong spot.

There are plenty of scenarios in which people can — and do — misspell their own names on income tax forms. Such a simple error can lead to rejected returns and delayed refunds.

In addition, if you recently married or divorced and haven’t registered a name change with the Social Security Administration, be sure to use your previous name. The name on your forms needs to match the name listed in Social Security records.

Mistake No. 4: Making math errors

This becomes less of a problem if you use software to prepare and file your taxes. The computer will do all the calculations on your behalf, which virtually guarantees you’ll get it right.

However, the computer can’t know whether the numbers you’ve entered are correct. Double-check everything to be sure your return is accurate. It should also go without saying that if you’re still doing a paper return, use a calculator and do the math twice to confirm the results.

Mistake No. 5: Forgetting your John Hancock

There are two places this mistake can trip you up.

This first is by failing to sign a paper return before mailing it. The second is failing to sign your check if you’re sending in a payment. Either one can result in lengthy delays in processing your return.

You can avoid this mistake by filling in and signing your return electronically and having tax payments directly withdrawn from your bank account. This saves on postage too.

Mistake No. 6: Selecting the wrong filing status

This mistake may be most common for single parents.

For example, an unmarried parent who has a qualifying dependent and pays more than half the cost of keeping a home may be able to file as a head of household, a status that boosts the standard deduction.

For married couples, filing jointly is usually most advantageous, but that’s not always the case. So if you are married, don’t just assume that your filing status should be married filing jointly, as opposed to married filing separately. We get into the nitty-gritty of this in:

• “8 Benefits of Filing a Joint Tax Return“
• “7 Times When Married Couples Should File Taxes Separately“

Mistake No. 7: Missing valuable deductions or credits

It’s not enough to simply use the right form and the right filing status. If you want to maximize your refund, you also need to take advantage of every tax deduction and credit available to you.

There are plenty of credits and deductions that have the potential to reduce your tax liability by thousands of dollars.

Your tax software or tax professional should help ensure you don’t miss anything you’re entitled to, but you should learn the names of some of the biggies.

Mistake No. 8: Failing to claim all of your income

You might also make the mistake of thinking you don’t need to claim income unless you receive a W-2 or 1099 form. However, you’re supposed to claim all income for the year, including side jobs, gambling winnings and just about any money you have made in any other way.

Cheating Uncle Sam may seem like a victimless crime, but you’ll feel victimized if you’re ever audited and such omissions are discovered.

Mistake No. 9: Sending your return through the mail

If you insist on being old-school and send your return through the U.S. mail, you’re making the final mistake on our list.

Filing through the mail is a mistake for many reasons. First, if you’re filing a paper return, you increase the chances of making one of the other mistakes listed above.

Using software means lower odds of missing Social Security numbers, forgetting to sign your return and making math errors.

In addition, a good software program will help you root out deductions and credits you might otherwise miss. It should also guide you to the right filing status.

Filing electronically means you could have your refund cash in hand much sooner. If you’re not already e-filing, it’s time to get on this bandwagon.