What Is a "B" Notice? What Must I Send This Notice?
A "B" notice is a backup withholding notice IRS stating that the non-employee's taxpayer ID number is either missing or incorrect. Send this notice when you receive notice from the IRS that the taxpayer ID is missing or incorrect. When you receive the first IRS notice, you must:
- Immediately start withholding taxes at the rate of 28% from that non-employee's pay, no later than 30 days after you receive the notice
- Send a copy of the "B" notice to the individual.
- Send the individual a W-9 form and request that it be completed and returned to you to send to the IRS.
What is a Second "B" Notice? When Do I Send This Notice?
The second B notice tells the individual taxpayer to contact the IRS or Social Security Administration to obtain a correct Taxpayer ID Number. You as the employer are not required to do anything except continue to withhold income tax from the taxpayer's payments.
What Is a "C" Notice? What Must I Do When I Receive This Notice?
A "C" notice is a backup withholding notice from the IRS stating that the non-employee has understated income and is subject to backup withholding. When you receive the first "C" notice, you must:
- Immediately start withholding taxes at the rate of 28% from that non-employee's pay, no later than 30 days after you receive the notice
- Send or give a copy of the "C" notice to the individual.
When in doubt as to what to do, always start backup withholding on payment made to an individual (at the rate of 28%). Let the taxpayer sort out the taxpayer ID problem with the IRS.

