Tax Problems and Solutions Handbook
Taxpayer Protection Program notification to a taxpayer to verify their return by phone. Advises taxpayers that a return was received with their name and Social Security Number (SSN) and that to protect them from identity theft, their identity needs to be verified before processing the return. Taxpayers receiving this letter are required to call the TPP telephone line to authenticate their identity.
Updated: July 15, 2025
Systemically issued to acknowledge receipt of Form 14039 or similar statement attached to a paper return.
Updated: July 15, 2025
Notifies taxpayer that they may be a victim of employment-related tax identity theft because someone is using their SSN for employment.
Updated: July 15, 2025
In mid-December, the IRS issues a CP01A notice providing the six-digit IP-PIN and filing instructions to select taxpayers meeting specific tax identity theft criteria.
Updated: July 11, 2025
Used to acknowledge receipt of Form 14039 substantiating a claim of identity theft and to notify taxpayers of the action taken by the Service with regard to their tax records (indicator put on the taxpayer’s account). No further action is required. IRS can issue Letter 4445C as a substitute for CP01.
Updated: July 15, 2025
Letter notifying the taxpayer of a withdrawal or notifying the third-party of a revocation.
Updated: July 15, 2025
Letter to taxpayer or authorized representative when an authorization is incomplete for the taxpayer or an authorization is incomplete for a third-party.
Updated: July 15, 2025
Letter to tax professional or authorized third-party generated when a new CAF number is issued.
Updated: July 29, 2025
SFR contact letter from the Examination Division that includes the Form 4549 Examination Report with the additional assessment and penalties proposed.
Updated: July 11, 2025
Second notice to file a past due return.
Updated: July 11, 2025
