Tax fraud, including issues such as tax evasion, false reporting on tax forms or failing to report income is perhaps one of the most common types of crimes in the United States but also the one that is least often formally charged. It can also include failure to pay taxes collected through state or federal taxes to the appropriate government or failing to charge taxes for taxable sales and purchases. Tax fraud penalties for those that are charged can be very significant including restitution of back taxes and interest, substantial fines and jail time or a combination of all possible sentencing options. Tax fraud issues are handled by the Internal Revenue Service and are typically first identified by an anomaly on a tax return, a dramatic decrease in taxable income or a marked change in some aspect of filing by either an individual or a company. The other major source of tax fraud discovery includes reporting by others, often employees, friends or family members.