IRS letter help
Got an IRS CP2100 or CP2100A Notice? What It Means and What to Do
This notice goes to businesses that file information returns. It lists payees whose name or taxpayer identification number did not match IRS records, and it can require you to start backup withholding.
Reviewed by LaToya Clark-Thompson, FounderLast updated
What this letter is
The CP2100 and CP2100A tell a payer that some of the information returns it filed, usually Forms 1099-NEC, 1099-MISC or 1099-INT, have a payee name or taxpayer identification number (TIN) that is missing or does not match IRS records. The notice comes with a list of the affected payees.
The two versions carry the same instructions. The IRS sends the CP2100 to payers with a large number of mismatched returns and the CP2100A to payers with fewer. The IRS issues these notices twice a year.
Why you got it
- A contractor gave a business name with a personal Social Security number, or the reverse
- The TIN was typed with a transposed digit
- A sole proprietor’s trade name was entered instead of the name the IRS has on file
- Form W-9 was never collected, so the 1099 went out with a blank or guessed number
- A payee changed their legal name and never updated it with Social Security
What to do now
- Compare the list on the notice with your own vendor records
- If your records do not match the list (you made an entry error), correct your records. The IRS says not to call or write to tell it you made the correction
- If your records do match the list, send the payee the appropriate “B” notice; Publication 1281 has the wording and copies
- For a missing or obviously incorrect TIN, start backup withholding right away, and request the TIN as the rules require so you can avoid a penalty
- If a payee does not respond, begin backup withholding on future payments no later than 30 business days after you received the CP2100 or CP2100A
- When the payee gives you a TIN, stop backup withholding no later than 30 calendar days after you receive it
What happens if you ignore it
If you are required to backup withhold and do not, the business can be held liable for the amount that should have been withheld. Penalties can also apply for filing information returns with incorrect or missing TINs. Backup withholding that is collected has to be deposited on your regular deposit schedule and reported on Form 945, under the same name and EIN as your information returns.
How we help
We reconcile the notice list against your vendor file, draft the B notices for the payees who need them, and set up W-9 collection so the next round of 1099s goes out clean. If backup withholding has to start, we set it up in the payment workflow and handle the Form 945 reporting through our payroll services. Ongoing vendor records are part of our bookkeeping work.
If your 1099s were late, missing or wrong for earlier years, missed 1099s explains how they are caught up. Payroll deposit problems are a separate and more serious matter; see Letter 1153. If the IRS later proposes information return penalties and you want someone to speak for the business, that is the independent licensed CPA we work with, with our office coordinating.
What to send us
- Every page of the CP2100 or CP2100A, including the payee list, through the secure client portal
- The W-9s you have on file for the listed payees
- The 1099s you filed for the year in question, or access to the system that filed them
- Your vendor list, so we can find other payees with the same problem before the next filing
Frequently asked questions
What is a B notice and when do I send one?
A B notice is the letter a payer sends to a payee whose name and TIN did not match IRS records, asking them to confirm or correct it. You send it when the name and TIN on the CP2100 list match what is in your own records. Publication 1281 has the required wording for the first and second B notices.
Do I have to tell the IRS I fixed the TIN?
No. The IRS says you do not need to call or write to report corrections to your records, and you do not need to send it corrected TIN information. Fix your vendor file, use the correct details on future information returns, and follow the B notice and backup withholding steps for anyone still on the list.
How does backup withholding work for a contractor?
You hold back a flat rate set by law from each payment to that payee, deposit it with the IRS on your normal deposit schedule, and report it on Form 945. The amount also appears on the payee’s 1099. It continues until the payee gives you a valid TIN, then stops within the window the IRS sets.
Why did I get a CP2100 when my contractor filled out a W-9?
The W-9 may have had a trade name that does not match the TIN, the wrong type of number, or a typo. A W-9 is only as good as what the payee wrote on it. The IRS TIN matching program, available to payers who file information returns, lets you check names and numbers before you file.
Not the question you had? The full tax FAQ covers more ground, and our client reviews say what the work is actually like.
Related pages
Letter 1153 (trust fund recovery penalty)
A proposal to hold you personally liable for a business’s unpaid payroll taxes. An appeal window applies.
Learn moreHow to read an IRS letter
Where the notice number, tax year, amount and response date sit on the page, and what each means.
Learn moreIRS penalty relief
The Automatic Exemption from Penalty, which replaces First-Time Abate, and reasonable cause relief.
Learn moreHow to respond to an IRS letter
Check it, decide whether you agree, gather support, reply by the date, and keep proof.
Learn morePart of IRS & SC Letter Help. Not sure which service fits? Answer a few questions.
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