When you own a single-member LLC, the IRS doesn't require that taxes be filed by the LLC; the IRS requires taxes to be filed by the member on his/her own personal return. Therefore, the IRS doesn't ask for any sort of identifying number for the LLC. That's true even if you do have an EIN in the name of the LLC - the 2023 Instructions for Schedule C (2023) clearly state that the only EIN that should appear on Schedule C is one issued to you in your own name as a sole proprietor.You do not need to include any additional information on your personal return.