LLCs are not an IRS thing, they are inventions of a state legislature. As far as the IRS is concerned, an LLC is taxed as a partnership (if more than one owner), as a corporation (if the taxpayer chooses), or as a sole proprietorship (if there is only one owner and he/she otherwise qualifies). Note that in community property states, there are special rules for LLCs owned by two spouses who work in the business; these can also be reported as two "sole proprietorships".
Many LLCs are formed nowadays by sole proprietors who are looking for the legal protection of a "corporation" (NOTE: this protection varies state by state so getting legal advice here would be wise). This is what I was referring to: an LLC taxed as a "disregarded entity" (i.e., the IRS ignores the state-based incorporation as an LLC but is considered a sole proprietorship (Schedule C)) normally does not need an EIN.
Here are the reasons that the IRS suggests for getting an EIN; can you answer "Yes" to any of the following questions?
Do you have employees?
YES NO
Do you operate your business as a corporation or a partnership?
YES NO
Do you file any of these tax returns: Employment, Excise, or Alcohol, Tobacco and Firearms?
YES NO
Do you withhold taxes on income, other than wages, paid to a non-resident alien?
YES NO
Do you have a Keogh plan?
YES NO
Are you involved with any of the following types of organizations?
- Trusts, except certain grantor-owned revocable trusts, IRAs, Exempt Organization Business Income Tax Returns
- Estates
- Real estate mortgage investment conduits
- Non-profit organizations
- Farmers' cooperatives
- Plan administrators
YES NO
Please see https://www.irs.gov/businesses/small-businesses-self-employed/do-you-need-an-ein
