What Letter 6112 is
From the Campus Backup Withholding unit in Covington, KY. Encloses a List of Payees showing every 1099 you filed with a blank payee TIN (or with box 4 withholding) and the backup withholding the IRS computed at 24% of the payments. Selected from Payer Master File data, not from a CP2100 (IRM 4.19.26).
Where this sits: these notices come from the Form 945 side of the house, the return on which backup withholding is reported and deposited. The Form 945 page covers the account mechanics behind them.
The deadline
30 days on the letter; the IRS's internal cut-off is 45. One 30-day extension is available and it is always 30 days.
What to do
Respond in writing with a signed statement that the payee TINs were on file when the payments were made, plus the TINs (dated W-9s are the cleanest proof). Supplying the TINs now, or filing corrected 1099s, is not a defense. Never truncate TINs in the response.
How a payer ends up on the list
Every Form 1099 you file carries a payee TIN field. When it is blank, the IRS can see at a glance that backup withholding should have applied, because a payee who has not furnished a TIN is subject to 24 percent withholding from the first payment (the 60-day grace period in the regulations applies only to interest and dividend accounts where the payee has certified that a TIN has been applied for). The compliance check program compares the 1099s filed with a blank TIN, plus any that show withholding in box 4, against the payer's Form 945 for the same year. A payer that filed no Form 945, or one that reported less than 24 percent of the blank-TIN amounts, receives Letter 6112 with the computation attached. The selection comes from the payer's own filings, not from a CP2100, which is why a payer can receive a 6112 having never seen a B-Notice.
The IRS's position is simple: either the TIN was on file when you paid and you left it off the return (a filing error, and a 972CG matter), or it was not and you owed the withholding. The response has to say which, payee by payee.
Building the response
The response is a signed statement under penalties of perjury listing each payee on the enclosed list, the TIN you held, and the date you obtained it, with the W-9 or TIN Matching record attached. Dates matter more than anything else: a W-9 signed after the payment date proves nothing about that payment. Do not truncate TINs in the response, and do not simply send corrected 1099s with the TINs filled in, which the IRS treats as an admission that the TINs were not on the original returns. For payees who never furnished a TIN, the fallback is Form 4669 from each payee showing that they reported the income, collected on a Form 4670; it relieves the tax, though a penalty for failing to withhold can still apply. Where neither route works, agree the figure or file your own Form 945 for the year rather than wait for the Letter 6112-A. The compliance check guide covers the whole process; the missing-TIN exposure calculator estimates what the list will cost before you open it.
Questions about Letter 6112
Who receives Letter 6112?
Payer. From the Campus Backup Withholding unit in Covington, KY.
What is the deadline on Letter 6112?
30 days on the letter; the IRS's internal cut-off is 45. One 30-day extension is available and it is always 30 days.
What should I do when Letter 6112 arrives?
Respond in writing with a signed statement that the payee TINs were on file when the payments were made, plus the TINs (dated W-9s are the cleanest proof). Supplying the TINs now, or filing corrected 1099s, is not a defense. Never truncate TINs in the response.
Is Letter 6112 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.