CP40

A CP40 says the IRS has assigned an unpaid balance to a private collection agency, as the law requires for certain accounts. The notice names the agency and includes a Taxpayer Authentication number used for two-way verification — the legitimate agency must prove itself to you just as you do to it.

“This private agency now handles collection of your balance. Verify each other using the authentication number on this notice. You can work out payment with them — or pay the IRS directly at any time.”

The practical caution is impersonation: scam callers imitate exactly this situation. The genuine agency is named on the notice, appears on the IRS's private-debt-collection page, sends its own confirmation letter, and never demands unusual payment methods. Payment always remains possible directly to the IRS.

• The notice, with the agency name and authentication number
• The agency's own confirmation letter when it arrives
• Your records of the underlying balance
• Notes from any calls, in case verification fails

• Verifying the assignment is genuine before anything is discussed
• Deciding whether to resolve with the agency or move the matter back onto IRS terms
• Negotiating the payment arrangement
• Screening out impostor contact entirely