What CP 566 is
The suspense notice on a Form W-7 the ITIN unit finds "not processable" because "additional information must be submitted" (IRM 3.21.263.5.9, Jan. 30, 2025). The applicant has 120 days to respond, raised from 45 days in 2025, and the application rejects systemically at 140 days (IRM 3.21.263 Material Changes (11), (42), (76)). Form 14415 is the substitute in military cases where notarized identification is allowed. Common triggers a payer would recognize are missing exception documentation (reject R 19) and invalid exception documentation (R 21), for example a 1042-S or 1099 copy offered in place of a withholding agent letter (IRM 3.21.263.5.8.2, June 20, 2024; 3.21.263.6.3.5.2(9), Aug. 28, 2025).
The deadline
120 days for the applicant to respond; systemic reject at day 140.
What to do
A payer is not a party to the notice, but a payee who shows you one is usually short the document only you can supply. If the application rests on a reporting or withholding exception, give the payee a signed letter on letterhead naming them and stating the requirement for an ITIN for current-year distributions subject to withholding or reporting; the manual says information statements "are generally prepared once a TIN has been supplied" and are not accepted as exception evidence. Expect seven to eleven weeks of processing after the response, and keep backup withholding in place until a TIN arrives.
The W-7 process and why applications stall
An ITIN is requested on Form W-7, filed by mail with original or certified identity documents, through an IRS-authorized Certifying Acceptance Agent, or in person at a Taxpayer Assistance Center. The application must show why the applicant needs a number: either a federal return is attached that requires one, or the applicant qualifies for one of five exceptions, the first of which covers people who receive U.S. income subject to withholding or reporting (interest, dividends, pensions, annuities, royalties, rents, partnership distributions) but have no return to file. An exception application has to be documented, and the documentation for Exception 1 is a letter from the withholding agent or payer. CP 566 is the suspense notice: the application is incomplete, the notice says what is missing, and the applicant has 120 days to supply it before the application rejects automatically. The two reasons a payer will recognize are missing exception documentation and invalid exception documentation, the second usually meaning the applicant sent a copy of last year's 1099 or 1042-S instead of a letter, which the IRS does not accept because those forms are produced after a TIN exists.
The letter only you can write
A payee who shows you a CP 566 citing exception documentation is asking for a letter from you. It goes on your letterhead, names the payee as they appear on the W-7, states that they hold an account or contract with you that will generate distributions subject to IRS information reporting or withholding in the current year, identifies the type of income, and is signed and dated. The withholding agent ITIN exception letter is a ready template. Give it to the payee promptly, because their 120 days are running and processing after the response takes another seven to eleven weeks. Until the ITIN is assigned, the payee has no TIN and backup withholding applies to reportable payments at 24 percent, or chapter 3 withholding at 30 percent for a nonresident on a W-8; the backup withholding guide covers the mechanics, and the ITIN guide covers the exception rules and what the letter has to say.
Questions about CP 566
Who receives CP 566?
Payee. The suspense notice on a Form W-7 the ITIN unit finds "not processable" because "additional information must be submitted" (IRM 3.21.263.5.9, Jan.
What is the deadline on CP 566?
120 days for the applicant to respond; systemic reject at day 140.
What should I do when CP 566 arrives?
A payer is not a party to the notice, but a payee who shows you one is usually short the document only you can supply. If the application rests on a reporting or withholding exception, give the payee a signed letter on letterhead naming them and stating the requirement for an ITIN for current-year distributions subject to withholding or reporting; the manual says information statements "are generally prepared once a TIN has been supplied" and are not accepted as exception evidence. Expect seven to eleven weeks of processing after the response, and keep backup withholding in place until a TIN arrives.
Is CP 566 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 77 in the order they tend to arrive.