1099's to a single member LLC should be using the taxpayer's SSN not the business EIN, otherwise the IRS matching does not work. The LLC is "disregarded entity" when being reported as part of the owners tax return.

https://www.irs.gov/businesses/small-businesses-self-employed/single-member-limited-liability-compan...

provides the following (Emphasis to the last line added)

Taxpayer Identification Number

For federal income tax purposes, a single-member LLC classified as a disregarded entity generally must use the owner's social security number (SSN) or employer identification number (EIN) for all information returns and reporting related to income tax. For example, if a disregarded entity LLC that is owned by an individual is required to provide a Form W-9, Request for Taxpayer Identification Number (TIN) and Certification, the W-9 should provide the owner’s SSN or EIN, not the LLC’s EIN.