What is an IRS CP2100/CP2100A notice?

The IRS CP2100 and CP2100A notices are also known as “B Notices” (Backup Withholding Notices). They are sent to payers when the IRS identifies incorrect or mismatched taxpayer identification numbers (TINs) and names on information returns—most commonly 1099 forms or W-2G forms.

Why did I receive a CP2100/CP2100A notice?

You may receive a CP2100/CP2100A notice if:

• The TIN and name provided on a Form 1099 do not match IRS or Social Security Administration records.

• A TIN is missing or invalid.

• You filed returns with incorrect recipient information.

The notice requires you, as the payer, to take action by requesting correct information from your payees.

CP2100 vs. CP2100A – what’s the difference?

• CP2100: Sent when you have a large number of mismatches.

• CP2100A: Sent when you have a small number of mismatches.

What do I need to do?

When you receive a CP2100/CP2100A notice, you must:

1. Notify the payee of the mismatch by sending them a “B Notice.” First, within 15 days, Second, if no response within 30 days

2. Request a new W-9 form from the payee to correct their information.

3. Begin backup withholding (24%) on future payments if a valid TIN is not provided.

4. Correct and refile the affected 1099s with accurate information.

Failing to act on a CP2100/CP2100A may result in IRS penalties and continued mismatches in future filings.

How TaxBandits helps with CP2100/CP2100A notices

When you receive an IRS CP2100/CP2100A, the first step is to upload the notice into your TaxBandits account. This keeps your records organized and allows you to access actionable guidance on what the notice means and how to resolve it. You’ll know exactly what steps to take without having to figure it out on your own.

Plus, TaxBandits gives you the tools to prevent and resolve TIN mismatches effectively:

• Use the free W-9 Manager to collect and update W-9s from your payees quickly and securely.

• Run Recipient TIN Matching to validate TIN/name combinations against IRS records before you file, reducing the chance of errors.

• Once corrected W-9s are collected, you can e-file corrected 1099s directly through TaxBandits.

By combining W-9 collection, TIN validation, and correction filing in one platform, TaxBandits makes it easier to handle CP2100/CP2100A notices without relying on multiple systems or manual workarounds.