B Notice – What to Do When You Receive an IRS CP2100 Notice
You must send a “B Notice” to the affected payee to correct their information.
- First B Notice: Send this when you get the first CP2100/CP2100A for a payee within three years. Include Form W-9 so the payee can provide the correct name and TIN.
- Second B Notice: Send if it happens again within three years. The payee must contact the SSA or IRS to validate their TIN—no Form W-9 this time.
If the payee doesn’t respond within 30 business days, you must begin backup withholding at 24 percent until a valid TIN is provided.
To prevent future issues, always collect a signed Form W-9 from payees and use the IRS TIN Matching Service before filing. You can also review our IRS Publication 1281 summary for additional context on backup-withholding rules.
For complete details, refer to IRS Publication 1281 (PDF).
Updated for 2025 based on IRS Publication 1281 (Rev. 12-2023).
Disclaimer
The information provided on Accounting Portal is for general informational and educational purposes only and does not constitute professional accounting, tax, financial, or legal advice.
While we strive for accuracy and timeliness, no representation or warranty is made regarding completeness or reliability. Always consult a qualified professional before making any business, tax, or financial decisions.
Neither Accounting Portal nor its authors are liable for any loss or damage resulting from the use of this information.
© 2025 Accounting Portal. All rights reserved.