According to the IRS, returns are chosen for examination by computer scoring, information received from third party documentation (W-2, 1099 questionable treatment of an item), information received from other sources on potential non-compliance (newspapers, public records and individuals). 

A computer program called the Discriminant Inventory Function System (DIF) assigns a numeric score to each individual and some corporate tax returns after they have been processed. If your return is selected because of a high score under the DIF system, the potential is high that an examination of your return will result in a change to your income tax liability.

Your return may also be selected for examination on the basis of information received from third-party documentation, such as Forms 1099 and W-2, that do not match the information reported on your return.

If you have any questions regarding accounting, domestic taxation, essential business accounting, international taxation, IRS representation, U.S. tax implications of Real Estate transactions or financial statements, please give us a call at 305-274-5811.

Source: IRS