Got a scary phone call saying you owe a lot of money to the Internal Revenue Service?

It is a scam.

Tax experts can say that with confidence, without knowing any of the details, because the IRS does not solicit payments by phone. It will not send emails. If the agency needs information from you, they write a letter first.

The fact that this is easy to find out does not stop scammers from telephoning millions of Americans to get personal information. And it does not stop people from falling for it.

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In one scam still operating, 896,000 people have been called by would-be swindlers, and more than 5,000 victims have handed over $26.5 million, the IRS says.

Even tax accountants must work hard to avoid fraudsters in the run-up to the annual filing deadline, which is April 18 this year. In Maine and Massachusetts, the tax deadline is April 19.

Jeffrey Schneider, an enrolled agent for SFS Tax & Accounting Services in Port St. Lucie, Florida, gets called regularly by con artists saying they are IRS agents.

"I ask for their ID numbers, and they give me four numbers. Then I say, 'That's not the right kind of ID,'" Schneider says.

Here are four ways to avoid tax scams:

1. Shred, shred, shred

Be sure to shred all documents containing personal information, such as your Social Security number, home address, and birth date.

Spend a little extra and get a cross-cut shredder, says Schneider. That is because a straight-cut shredder is still tempting for thieves - they can take the shreds out of the garbage and piece them back together. If you use a professional preparer, make sure he or she cross-cut shreds documents, too.

"I shred with a professional company," says Schneider. "A truck comes and they do it right in front of me."

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2. Follow the two Es

File early and file electronically.

"If you can beat the fraudster, they can't file on your behalf," says Jason Witty, chief information security officer for U.S. Bancorp.

A 2011 audit found that the IRS paid out $5.2 billion in refunds to scammers in 2011, even as it blocked about $6.5 million from getting into the wrong hands.

Filing electronically can help keep your financial information secure by making sure a paper document with your Social Security number, address, salary and bank account information does not get diverted through the mail.

At tax preparer Jackson Hewitt, about 80 percent of customers now use e-file, says chief tax officer Mark Steber. "The days of old where you used the post office, that's not efficient," Steber says.

3. Get smarter about phishing

Tax scammers come at all angles.

Michael Kaiser, executive director of the National Cyber Security Alliance, says one new scam is an email that seems to come from your payroll service, saying your W-2 form was compromised in a data breach. It asks you to click to find out how to protect yourself, and then once you do, it asks you for your Social Security number.

The best way to avoid these scams is to be aware and to not readily give out your Social Security number, especially via email, says Kaiser.

That extends to how you communicate with your tax professionals emailing documents back and forth. Your preparer should password protect the documents and have a secure server.

4. Know your relatives

Even if you avoid being taken to the cleaners by strangers, there could be dangers lurking in your own home.

"The truth is that a lot of ID theft is people who know each other," says Kaiser.

They will probably know where you store sensitive information and have answers to easy security questions like your first pet.

"We don’t want people to distrust family members, but people should be aware of that, anyone who has access is somebody who could possibly use that information," Kaiser says.

If you were counting on the IRS's 6-digit Identity Protection PIN, which uses a personal identification number to help lock out fraudsters, you are out of luck. The system was pulled down last week for a security review, according to the IRS. The agency said it had already stopped 800 fraudulent returns among the 2.7 million PINs issued so far for the current filing season.

Security journalist Brian Krebs, who exposed some of the vulnerabilities on his website (, says the system has fundamental flaws based on the type of personal information it uses that is too easily bought for $2 a pop on the Internet.

"I doubt they'll bring it back," he says.