An EIN takes the form 12-3456789. It is for business use only. An owner still uses their own Social Security number or ITIN on their personal return. A business keeps the same EIN when it changes its name or elects a new tax classification.
Corporations and partnerships must have an EIN, even with no employees. An LLC with two or more members is a partnership by default, so it needs one as well. A business without an EIN that starts paying wages must apply for one by the seventh day after its first payday.
Not every LLC needs an EIN of its own. A single-member LLC is disregarded by default, and it can use its owner’s number for income tax. It generally needs its own EIN only if it has employees, owes excise tax, elects corporate tax treatment or is foreign-owned. It may still get one for a bank account or a state filing.
The IRS issues EINs for free and warns against websites that charge for one. Form the LLC or corporation with your state first, then apply with the IRS online tool. An approved application gets its number at once.
To apply online, the business must be formed and based in the US or a US territory. The application also needs the responsible party’s SSN or ITIN. On weekdays, the tool is open from 6 a.m. to 1 a.m. Eastern time. By fax, Form SS-4 takes about four business days.
Sources
- 26 C.F.R. § 301.6109-1, Identifying numbers
- 26 C.F.R. § 31.6011(b)-1, Employers’ identification numbers
- IRS, Instructions for Form SS-4 (Rev. December 2025)
- IRS, Get an employer identification number
Reviewed and updated September 2026. General information, not advice for your situation.