TAS: Taxpayer Advocate Service
TBD: To Be Determined
TBOR: Taxpayer Bill of Rights
TC: Tax Court
TC: Team Coordinator
TC: Transaction Code
TCMP: Taxpayer Compliance Measurement Program
TDA: Taxpayer Delinquency Account
TDI: Taxpayer Delinquency Investigation
TE: Tax Examiner
TEC: Taxpayer Education & Communication
TEFRA: Tax Equity Fiscal Responsibility Act
TEGE: Tax Exempt & Governmental Entities
TFRP: Trust Fund Recovery Penalty
TGR: Total Gross Receipts
TIF: Taxpayer Information File
TIGTA: Treasury Inspector General for Tax Administration
TILT: Taxpayer Inquiry Look-up
TIN: Taxpayer Identification Number
TLN: Transmittal Locator Number
TM: Technical Memoranda
TM: Territory Manager
TP: Taxpayer
TPBC: Transactional Processing Branch Chief
TPCO: Transactional Processing Center Operations
TPI: Total Positive Income
TRA'86: Tax Reform Act of 1986
TRR: Tax Resolution Representatives
TT&L: Treasury Tax and Loan
TY: Tax Year
UNAX: Unauthorized Access
UNISTAR: Unified System for Time and Appeals Records
UPC: Unpostable Code
URB: Underreporter Branch
USTC: United States Tax Court
W&I: Wage and Investment
WCC: Workers' Compensation Center