IRS Audit Red Flags: The Dirty Dozen

Ever wonder why some tax returns are eyeballed by the Internal Revenue Service while most are ignored?

The IRS audits only slightly more than 1% of all individual tax returns annually. The agency doesn't have enough personnel and resources to examine each and every tax return filed during a year. So the odds are pretty low that your return will be picked for review. And, of course, the only reason filers should worry about an audit is if they are fudging on their taxes.

However, the chances of being audited or otherwise hearing from the IRS increase depending upon various factors, including your income level, whether you omitted income, the types of deductions or losses you claimed, the business in which you're engaged and whether you own foreign assets. Math errors may draw IRS inquiry, but they'll rarely lead to a full-blown exam. Although there's no sure way to avoid an IRS audit, you should be aware of red flags that could increase your chances of drawing unwanted attention from the IRS.

[More from Kiplinger: They Tried to Deduct What? 10 Unbelievable Tax Deductions]

1. Making too much money

Although the overall individual audit rate is about 1.11%, the odds increase dramatically for higher-income filers. 2011 IRS statistics show that people with incomes of $200,000 or higher had an audit rate of 3.93%, or one out of slightly more than every 25 returns. Report $1 million or more of income? There's a one-in-eight chance your return will be audited. The audit rate drops significantly for filers making less than $200,000: Only 1.02% of such returns were audited during 2011, and the vast majority of these exams were conducted by mail. We're not saying you should try to make less money -- everyone wants to be a millionaire. Just understand that the more income shown on your return, the more likely it is that you'll be hearing from the IRS.

2. Failing to report all taxable income

The IRS gets copies of all 1099s and W-2s you receive, so make sure you report all required income on your return. IRS computers are pretty good at matching the numbers on the forms with the income shown on your return. A mismatch sends up a red flag and causes the IRS computers to spit out a bill. If you receive a 1099 showing income that isn't yours or listing incorrect income, get the issuer to file a correct form with the IRS.

3. Taking large charitable deductions

We all know that charitable contributions are a great write-off and help you feel all warm and fuzzy inside. However, if your charitable deductions are disproportionately large compared with your income, it raises a red flag. That's because IRS computers know what the average charitable donation is for folks at your income level. Also, if you don't get an appraisal for donations of valuable property, or if you fail to file Form 8283 for donations over $500, the chances of audit increase. And if you've donated a conservation easement to a charity, chances are good that you'll hear from the IRS. Be sure to keep all your supporting documents, including receipts for cash and property contributions made during the year, and abide by the documentation rules. And attach Form 8283 if required.

[More from Kiplinger: 14 Extraordinary Tax Deductions]

4. Claiming the home office deduction

Like Willie Sutton robbing banks (because that's where the money is), the IRS is drawn to returns that claim home office write-offs because it has found great success knocking down the deduction and driving up the amount of tax collected for the government. If you qualify, you can deduct a percentage of your rent, real estate taxes, utilities, phone bills, insurance and other costs that are properly allocated to the home office. That's a great deal. However, to take this write-off, you must use the space exclusively and regularly as your principal place of business. That makes it difficult to successfully claim a guest bedroom or children's playroom as a home office, even if you also use the space to do your work. "Exclusive use" means that a specific area of the home is used only for trade or business, not also for the family to watch TV at night. Don't be afraid to take the home office deduction if you're entitled to it. Risk of audit should not keep you from taking legitimate deductions. If you have it and can prove it, then use it.

5. Claiming rental losses

Normally, the passive loss rules prevent the deduction of rental real estate losses. But there are two important exceptions. If you actively participate in the renting of your property, you can deduct up to $25,000 of loss against your other income. But this $25,000 allowance phases out as adjusted gross income exceeds $100,000 and disappears entirely once your AGI reaches $150,000. A second exception applies to real estate professionals who spend more than 50% of their working hours and 750 or more hours each year materially participating in real estate as developers, brokers, landlords or the like. They can write off losses without limitation. But the IRS is scrutinizing rental real estate losses, especially those written off by taxpayers claiming to be real estate pros. The agency will check to see whether they worked the necessary hours, especially in cases of landlords whose day jobs are not in the real estate business.