The responsibility to prove entries, deductions, and statements made on your tax returns is known as the burden of proof. You must be able to prove (substantiate) certain elements of expenses to deduct them. Generally, taxpayers meet their burden of proof by having the information and receipts (where needed) for the expenses. You should keep adequate records to prove your expenses or have sufficient evidence that will support your own statement. You generally must have documentary evidence, such as receipts, canceled checks, or bills, to support your expenses. Additional evidence is required for travel, entertainment, gifts, and auto expenses. See IRS Publication 463, Travel, Entertainment, Gifts, and Car Expenses.
Prior to the Internal Revenue Service Restructuring and Reform Act of 1998, this responsibility, or burden of proof, was yours alone. The Restructuring and Reform Act of 1998 calls for a shift in the burden of proof to the IRS in a court proceeding. This shift to the IRS to prove an item on your tax return occurs only in a court proceeding and only if you have met your recordkeeping requirements. This means the rules related to the substantiation of deductions still apply, records required by law still need to be maintained, and you still need to cooperate with any reasonable request for information by the IRS.
