What CP 259 is
"CP 259 series notices (A - G) are issued from Master File on accounts that have not received a return to satisfy the filing requirement" (IRM 21.3.1.7.38, Oct. 1, 2026). The business delinquency check runs sixteen weeks after each return's due date and uses 1099 and Payer Master File data to pick cases (IRM 5.1.11.2.1). After one or two notices an unresolved module becomes a delinquent-return investigation. For a Form 945 there is a particular wrinkle: the IRS cannot prepare a substitute 945 under IRC 6020(b), so the case is referred to Examination, and a Form 945 filing requirement created by a misapplied deposit can produce a CP 259 for a return that was never owed.
The deadline
The notice gives a response date. There is no assessment yet; the exposure is the failure-to-file penalty once a return is filed or assessed, and for an unfiled withholding return the statute never starts.
What to do
File the return if it was owed, with payment of the tax shown. If no return was owed, respond saying so: no payments subject to withholding were made in the year, or the business has no Form 945 requirement, and ask that the filing requirement be closed; if a misapplied deposit created it, ask for the transfer and the removal together (IRM 21.5.8.4.4). If withholding will not recur, file a final Form 945 so the requirement ends.
Questions about CP 259
Who receives CP 259?
Businesses with an open filing requirement and no return posted, including a Form 945 requirement left open after withholding stopped. "CP 259 series notices (A - G) are issued from Master File on accounts that have not received a return to satisfy the filing requirement" (IRM 21.3.1.7.38, Oct.
What is the deadline on CP 259?
The notice gives a response date. There is no assessment yet; the exposure is the failure-to-file penalty once a return is filed or assessed, and for an unfiled withholding return the statute never starts.
What should I do when CP 259 arrives?
File the return if it was owed, with payment of the tax shown. If no return was owed, respond saying so: no payments subject to withholding were made in the year, or the business has no Form 945 requirement, and ask that the filing requirement be closed; if a misapplied deposit created it, ask for the transfer and the removal together (IRM 21.5.8.4.4). If withholding will not recur, file a final Form 945 so the requirement ends.
Is CP 259 about my own income tax?
No. This decoder covers information reporting and withholding: the notices a payer, filer or payee sees because of Forms 1099, W-2, 945 and the TINs on them. Individual income-tax notices follow a different track.
Have a different notice? The IRS notice decoder lists all 89 in the order they tend to arrive.