Based on the provided information, if you have recently formed a limited liability company (LLC) that has no employees, isn't subject to relevant excise taxes, and hasn't elected to be taxed as a corporation, you generally do not need a separate federal tax ID number (EIN) for the LLC.
For a single-member LLC that is disregarded as an entity separate from its owner for federal income tax purposes, the owner can use their social security number (SSN) as the taxpayer identification number. This is supported by the information that a sole proprietor without employees and who doesn't file any excise or pension plan tax returns doesn't need an EIN and can use their SSN instead.
However, if at any point the LLC hires employees or needs to file excise tax returns, it will then require an EIN. Additionally, if the LLC elects to be taxed as a corporation or an S corporation, it will need a new federal tax ID number.
In summary, under the current circumstances described (no employees, no excise taxes, and not electing corporate tax status), you do not need a separate federal tax ID number for your LLC.
Sources:
Publication 583 (1/2021)
§ 301.7701-3. Classification of certain business entities.
Publication 1635 (2/2014)
Instructions for Form SS-4 (12/2023)
Publication 3402 (3/2020)
