If you have questions about the Treasury Offset Program (TOP) or the notice you received from the U.S. Department of the Bureau of the Fiscal Service-Debt Management, contact the U.S. Treasury Offset Program (TOP) Call Center at 1-800-304-3107. Many state and federal agencies offset debts through TOP. The notice you received from the Department of the Bureau of the Fiscal Service-Debt Management will outline the name of the state agency (or agencies) that requested the offset of your federal income tax refund, along with contact information for those agencies. A letter is sent for each offset.