CP2100A tells a payer that fewer than 50 information returns contained a missing, incorrect, or unmatched payee name and TIN. CP2100 contains the same instructions but is used when there are 50 or more errors. The “A” does not mean this is a second B-notice.
Select the Correct B-Notice
Compare the IRS list with your records. For an account that matches the IRS list, use the payee's mismatch history to decide whether Publication 1281 requires a first or second B-notice. A first B-notice generally includes Form W-9; a second B-notice requires different verification from the payee.
Your Obligations
Begin backup withholding immediately when a TIN is missing or obviously incorrect and you have not already begun. For name/TIN mismatches, follow the B-notice timing and stop rules in Publication 1281. Report and deposit any backup withholding using the applicable information return and Form 945 procedures.
Liability for Non-Compliance
If you do not backup withhold when required, your business can become liable for the tax that should have been withheld. Keep the mismatch list, copies of B-notices, mailing records, new W-9s, and any IRS or Social Security verification in your compliance file.
Practical Steps
Update your accounting system to flag the affected payees for backup withholding. Notify the payees in writing that you're required to withhold 24% and explain how they can resolve the TIN mismatch. Keep copies of all B-notice correspondence as documentation of your compliance efforts.
If you've received a CP2100A and need help with compliance, call us at (813) 229-7100.