Letter 3667-C: Generic reply when a CP2100 is sent back to the IRS

What Letter 3667-C is

Sent when a copy of a CP2100 or CP2100A arrives attached to other correspondence. It explains what the notice is; it does not adjust anything. Correspondence about a CP2100 on its own is "unsolicited or erroneous" and is destroyed after 30 days (IRM 5.19.3.5.1.3). There is no procedure to contest a CP2100.

The deadline

None.

What to do

Do not write to the IRS about a CP2100. Fix your records, send the B-Notices the flowchart requires, and log what you did.

Why the IRS sends this letter at all

The CP2100 and CP2100A are informational. They tell a payer which name and TIN combinations on its information returns did not match IRS records; they do not propose a penalty, assess anything or ask for a reply. There is no office that reviews a payer's objections to a CP2100, no appeal, and no procedure for telling the IRS that a listed payee has since been corrected. The response the notice calls for is entirely on the payer's side: compare the list to your records, send the B-Notices the Publication 1281 flowchart requires, start backup withholding on the payees who do not respond, and keep the log.

Payers write in anyway, usually by stapling the CP2100 to a letter explaining that the TINs are right, that the vendor has been fixed, or that the notice must be a mistake. When that correspondence reaches a campus, the clerk has nothing to act on. Letter 3667-C is the acknowledgment that goes back: it restates what a CP2100 is and what the payer is supposed to do with it. Correspondence about a CP2100 that arrives alone is classified as unsolicited and destroyed after 30 days, so nothing you send is retained on your account.

Where your explanation does count

The place to make the case that your TINs were right, or that you solicited them properly, is the Notice 972CG that arrives a year or more later. That notice has a 45-day response window and is reviewed by a person. The evidence it asks for is exactly what the CP2100 season should have produced: dated W-9s, copies of the B-Notices and the mailing dates, the backup withholding start dates and the Form 945 that reported it. A payer who spends the CP2100 season arguing with the IRS instead of building that file arrives at the 972CG with nothing to show. The CP2100 guide covers what the IRS will and will not do with the notice in more detail.

Questions about Letter 3667-C

Have a different notice? The IRS notice decoder lists all 77 in the order they tend to arrive.