9.39 Filing False Tax Return is an illegal activity that involves intentionally filing a false or fraudulent tax return with the Internal Revenue Service (IRS). Types of 9.39 Filing False Tax Return may include providing false information or withholding information from the IRS, claiming false deductions, or claiming false income. This type of fraud can result in criminal penalties, including fines, imprisonment, or both. Additionally, the IRS may pursue civil charges, including monetary penalties and interest charges.