When someone tries to sell you a complicated scheme that promises to slash or eliminate your tax bill, think twice.

Scam promoters set up abusive tax shelters in which they move your income-producing assets -- including businesses you own -- into a trust, limited liability company (LLC), limited liability partnership (LLP), international business company (IBC), or foreign financial account.

The IRS said it also has been seeing frequent misuse of "captive insurance" arrangements.

Regardless of the structure, however, the basic idea is this: Once you put your assets into the shelter, a string of complicated transactions are conducted solely for the purpose of hiding your money from taxes and making it look like you can claim fat deductions, escape self-employment taxes, and shift money out of your taxable estate.

Sometimes taxpayers themselves perpetrate this scam. But business owners, physicians and other high net-worth filers can be snookered by someone who backs up a scheme with official-looking documents to make it seem legal.

Ask the promoter whether he's collecting a referral fee, and get a second opinion about the set up from a trusted, independent tax advisor.

If you get caught, it could mean large penalties, interest and even criminal prosecution.