I seem to recall confirming what numbers I put on the 1099-Misc to the IRS letter, and they had input it wrong. This is what you are told:

"What to do if you receive a CP2100 or CP2100A Notice?

Compare the listing(s) with your records.

• For missing TINs: Determine if you are already backup withholding on the account. If you are not, begin backup withholding immediately. You must make up to three solicitations for the TIN (initial, first annual, second annual) to avoid a penalty for failing to include a TIN on the Information Return.
• For incorrect TINs: Compare the accounts on the listing with your business records. If they agree, send the appropriate "B" Notice to the taxpayer (payee). If an account does not agree, this could be the result of a recent update, an error in the information you submitted, or an IRS processing error. If this is what happened, the only thing you should do is correct or update your records."

https://www.irs.gov/businesses/small-businesses-self-employed/backup-withholding-b-program