TIN ComplianceA resource from TIN Comply
From the IRS manual

Your CP2100: what the IRS will and will not do with it

Publication 1281 tells you what to do with a CP2100. The two IRS manuals behind the notice tell you what the IRS itself will do, which is much less than most payers assume: it keeps no record that you received it, it will not read a letter about it, it cannot tell you whether a listed payee is on a first or second notice, and if the envelope comes back it throws the notice away. Everything below is the IRS's own script.

Updated September 28, 2026Sources IRM 5.19.3 (July 30, 2025), especially 5.19.3.5.1 and Exhibit 5.19.3-1; IRM 21.3.11.6.2 (Nov. 21, 2025); IRM 3.42.9.13 (Dec. 5, 2025)Reading time 11 minutes

Which notice you get

Which forms it covers

The B-Notice program reads only nine form types: 1099-B, DIV, G, INT, K, MISC, NEC, OID and PATR (IRM 5.19.3.3(1)). A payer that files 1099-R, 1099-S, 1098 or W-2G will never receive a CP2100 for those returns, and, not by coincidence, those are also the only forms that make a payer eligible for the TIN Matching program. A "missing" TIN, in the manual's definition, is anything that is not exactly nine digits: an eight-digit number, a number with a letter in it, or all the same digit (22-2222222) is "obviously incorrect and is a missing TIN" (IRM 5.19.3.4.1.1(2); IRM 21.3.11.6.2.2).

There is no record that you received it

"There is no indicator on IDRS when the payor is subject to BWH 'B' for TIN-related problems" (IRM 5.19.3.4(6)). Unlike a payee on a C-Notice, who carries a status code on their account, a payer who receives a CP2100 leaves no trace on the IRS's systems. Two consequences. A phone assistor cannot tell you whether you received one, which payees were on it, or how many times a payee has appeared. And the burden of tracking first versus second notices sits entirely with you: "The CP notice does not identify whether it is the first or second notification for a particular account. Therefore, the payor is required under the backup withholding regulations to institute a system to track the status of these accounts" (Exhibit 5.19.3-1, Q1).

The IRS keeps no per-payer history of CP2100s. Your solicitation log is the only record that exists, for you and, later, for the penalty examiner.

You cannot contest it

There is no procedure anywhere in the manual for a payer to dispute a CP2100. Correspondence from a payer "with or without a CP 2100 or CP 2100A is considered to be unsolicited or erroneous correspondence. The payor is not to submit any correspondence" (IRM 5.19.3.5.1.3). Such letters are held 30 days and then destroyed as classified waste. If a copy of a CP2100 arrives attached to other correspondence, the campus replies with Letter 3667-C, a generic explanation of what the notice is. The manual also says the payer "is not required to write or call the campus" to report that a listed account was already corrected; the instruction is to fix your records and move on: "THE PAYOR DOES NOT HAVE TO DO ANYTHING ELSE" (IRM 5.19.3.5.1(4)).

The reason a listing can be wrong is stated too: "a recent update, a payor error in submission, or an IRS processing error," and "corrections may not be processed at the time the first run is done" (Exhibit 5.19.3-1, Q15). A payee you fixed before the run can appear on the list; you do not send a B-Notice for that account, and you document why.

First or second: the IRS will not tell you

The rules the manual gives its own staff (IRM 5.19.3.5.1(5); Exhibit 5.19.3-1, Q6, Q17, Q18):

  • A second notice is one received "within three calendar years" of the first, for the same name/TIN combination and account.
  • "Two notices received during the same year count as one notice." A payee on both the spring and fall listings gets one B-Notice.
  • A later CP2100 that relates to the same tax year's returns "must be disregarded." No second B-Notice.
  • You are "only required to track these accounts for three years after the date he received the B-Notice."

The TSO assistors are told the same thing from the other side: the notice "does not identify" first or second, and Publication 1281 "is your source of information" (IRM 21.3.11.6.2).

The script rules

SituationWhat the IRS tells its staffCite
The TIN was in your records but left off or mis-keyed on the returnFix your records and use it next year. "DO NOT send a B-Notice."Exh. 5.19.3-1 Q5
Sole proprietor listed under the business name, but you already have the individual's namePut the individual name on line 1 going forward; "they don't have to do a solicitation."IRM 21.3.11.6.2.3
Sole proprietor, individual name unknownSolicit. "The payor MAY NOT show only the business name for a sole proprietorship."Exh. 5.19.3-1 Q7
W-9 comes back with the same name and TIN after a first noticeKeep it on file; "Do not backup withhold." First notice only.Exh. 5.19.3-1 Q10
Payee has several accounts with the same bad TINWithhold on all accounts you can find with reasonable care; "a single certification may be used to correct all accounts."Exh. 5.19.3-1 Q20
You no longer pay the payeeSend the B-Notice anyway and note the account so a renewed relationship is tracked under the two-in-three rule.Exh. 5.19.3-1 Q6
B-Notice comes back undeliverableLook for a better address and re-mail; if none, "keep the undeliverable document with the payee's records and start BWH on any future payments."Exh. 5.19.3-1 Q11
Payee says the TIN is "applied for"60 days applies "only to interest, dividend, and certain payments relating to readily tradeable instruments." For 1099-NEC or MISC, withhold now.Exh. 5.19.3-1 Q14
Second notice: what clears itAn SSA card copy that shows a different name/SSN than the notice, or one issued no earlier than six months before the notice date; or Letter 147C for an EIN, which the manual says the payee must request in writing.IRM 5.19.3.5.1.2(5)-(6)
Nonresident alien payeeWithhold unless a Form W-8BEN is on file.Exh. 5.19.3-1 Q8
When to start withholdingNo later than 30 days after receipt for payees who do not respond; the payer "may elect, on a case by case basis, to start BWH at any time after receipt."IRM 5.19.3.5.1.1; Q16
Payee says you withheld by mistakeRefund only if it was your error and only before year-end and before the 1099 is furnished; otherwise the payee claims it on their return. Form 945 reports the un-refunded amount.Exh. 5.19.3-1 Q23

The manual's timing language is not uniform and should be kept that way: mail within 15 business days; return date on the notice no later than 30 business days; begin withholding no later than "30 days"; stop within 30 calendar days of receiving the W-9 (IRM 5.19.3.5.1.1 to 5.1.2). The deadline calculator applies Publication 1281's business-day reading.

Lost, late and misdirected notices

  • Undeliverable CP2100. The IRS looks once for a better address and re-mails the original notice with its original date. "No new address found: Destroy the CP2100/A notice." A CP2100 with a CD is destroyed with no address research at all (IRM 5.19.3.5.1.4). Keep Form 8822-B current; there is no second attempt.
  • Recreating a notice. Call the help desk at 866-455-7438 starting two weeks after the mailing date. Paper recreates are worked bi-weekly and mailed within 7 to 10 business days; listings are available for "4 years from original CP 2100/CP 2100A Notice Date" (IRM 5.19.3.5.1.5). TSO's own script says a notice "will not be verified until two weeks after the last dated notice for the tax year in question," and to expect a recreate "within 4 weeks" (IRM 21.3.11.6.2.6).
  • Sending it to a new address. Requires Form 8822-B faxed to TSO with the incident number written on top; the phone assistor cannot take a new address (IRM 21.3.11.6.2.6).
  • The Access Key EIN. Notices go to "the EIN used to generate the notices," which is the EIN the returns were filed under. If a service bureau or parent company filed under its own EIN, the notice went there, and a search on your EIN finds nothing (IRM 21.3.11.6.2.6). You are entitled to the business name behind the TCC on a notice you did receive (IRM 3.42.9.13.5).
  • Representatives. "Form 2848 or Form 8821 must be faxed in for each TIN" and for each notice type (IRM 21.3.11.6.2.6).

Corrections: what the IRS says not to file

Three instructions that answer the most common CP2100 question. "A payer SHOULD NOT file a correction merely to update the payee TIN on Form 1099 unless it is making a change to the dollar amount reported," and "A payer SHOULD NOT send the signed Form W-9 to the IRS" (IRM 5.19.3.5.1.1 Note). The TSO script: "The customer should not submit corrected files to the IRS, they only need to ensure their records are updated for the next filing" (IRM 21.3.11.6.2.2).

The one exception is the April mailing. Under what the manual calls the Spring Pass rule, a notice received in April may require a correction "for the immediate past filing season" if the same error carried into the return you just filed, but "a correction is not required for the tax year of the notice or any year prior" (IRM 21.3.11.6.2.4). Check whether the payee's current-season return repeated the error; if it did, correct that one and only that one.

Questions people ask

We have 30 bad TINs and never got a CP2100A. Are we clear?

No. The small-payer tier has a selection gate tied to 1099-MISC amounts and attorney fees, so a small payer can have mismatches the IRS never mailed about. The penalty program runs from the same data whether or not a CP2100 was sent. Run TIN matching before filing rather than waiting for a notice.

Can we call to find out if a payee was on last year's notice?

No. The IRS has no per-payer or per-payee record of B-Notices. It can recreate the listing itself, for four years, which is the only way to reconstruct history you did not keep.

The IRS's list is wrong; the payee's TIN was correct all along.

Then the account is a "recent update" or a "processing error" in the manual's terms. Do not send a B-Notice, do not write to the IRS (the letter is destroyed), and note the reason in your log. Run the pair through TIN matching and keep the code 0 result.