- Membership
- Certification
- Resources
- Events
- Community
- About
- Help
Handling W-9 TIN Mismatches After a CP2100 B-Notice
November 13, 2025
Q. We received a CP2100 and sent out a B-notice to one of our vendors and they gave us back a W-9. However, I ran it through the IRS tin matching services, and it came as a mismatch. What should I do? Do I resend it back to vendor and ask to correct it some type of way?
A.
(Answered by IOFM's third-party tax expert)
The best practice would be to ask the vendor for clarification. However, as long as they signed the W-9, there is no requirement on your side to do backup withholding. If there’s…
Become A Member
Join IOFM today as a Professional, Business, or Enterprise Member — or upgrade your Starter Membership — to get access to this content and thousands of other Articles, Webinars, Expert Answers, Resource Downloads, and more!
Naturally, this forum doesn’t allow the kind of full information exchange necessary for the Institute of Finance & Management (IOFM) to provide legal advice and the Expert is not a tax attorney in any event. Please understand that the nature of our responses are limited by these constraints as well as the site’s Terms of Use. If you have further questions or suggestions about how we can improve IOFM, please let us know.
Ask The Expert is a member resource of IOFM and all advice provided is subject to site’s Terms of Use.
What are you waiting for?
