Controlled Unclassified Information (CUI)

CUI Category: Federal Taxpayer Information

Category Description:

Related to returns and return information which are submitted, gathered or generated in conjunction with taxpayers’ responsibilities to comply with federal tax provisions in the United States Code. 

“Returns” includes information that is provided to the government pursuant to Title 26, including tax or information returns, declarations of estimated tax or claims for refund.  “Return information” includes a taxpayer’s identity, the nature, source or amount of income or any information received by, recorded by, prepared by or furnished to Internal Revenue Service relevant to the determination of tax liability including whether the taxpayer is the subject of investigation.  This protection extends to such items as medical, financial and other personal information submitted to the IRS by taxpayers.  Standards (typically tolerances, audit criteria and law enforcement techniques) related to the selection of returns for examination should only be disclosed to the extent their disclosure would not impair assessment, collection or enforcement under the internal revenue laws.  Tax data originating with the IRS generally retains its confidential status even when it resides with agencies other than the IRS.

Category Marking: TAX
Banner Format and Marking Notes:

Banner Format:

CUI//Category Marking//Limited Dissemination Control


Marking Notes:

  • Category Marking is optional when marking Basic CUI unless required by agency policy. Example: CUI//Limited Dissemination Control
  • Category Marking preceded by "SP-" is required when marking Specified CUI. Example: CUI//SP-Category Marking//Limited Dissemination Control
  • Whether CUI is Basic or Specified is determined by the applicable Safeguarding and/or Dissemination Authority for a given instance of CUI.
  • Separate multiple Category Markings by a single forward slash (/) and list Category Markings alphabetically. Example: CUI//Category Marking A/Category Marking B//Limited Dissemination Control
  • Category Markings for Specified CUI precede Category Markings for Basic CUI. Example: CUI//SP-Category Marking/Category Marking//Limited Dissemination Control
  • Separate multiple Limited Dissemination Controls by a single forward slash (/). Example: CUI//Category Marking//Limited Dissemination Control/Limited Dissemination Control
  • Reference 32 CFR 2002.20, CUI Marking Handbook, Limited Dissemination Controls and individual agency policy for additional and specific marking guidelines.



Notes for Safeguarding, Dissemination and Sanction Authorities:

  • CUI Specified authorities include specific handling practices that differ from general CUI requirements. For Specified authorities, reference individual Safeguarding/Dissemination control citations for distinct requirements
  • Whether CUI is Basic or Specified is determined by the applicable Safeguarding and/or Dissemination Authority for that CUI.
  • Each "Safeguarding and/or Dissemination Authority" citation links to the statute, regulation or government-wide policy authorizing the control of that information as CUI.
  • Each "Sanctions" authority links to the statute, regulation or government-wide policy that includes penalties for CUI misuse of CUI for the associated "Safeguarding and/or Dissemination Authority" on the same line.



Authority links are updated based on regular re-publication of the United States Code and Code of Federal Regulations, and the CUI Registry maintenance schedule.