No, you generally cannot use the same EIN for multiple LLCs. Each LLC is a separate legal entity created under state law, and the IRS assigns one Employer Identification Number per entity so that income, payroll, and tax payments are tracked to the right business. If you own three LLCs, you need three EINs. There is one narrow exception involving certain single-member LLCs, covered below.
One LLC, One EIN
IRS Publication 1635 establishes a one-to-one relationship between an EIN and a legal entity, meaning no two entities share the same number.1Internal Revenue Service. Understanding Your EIN Each set of articles of organization filed with a state creates a new taxpayer that must be registered independently, even when the same person or parent company owns all of them.2Internal Revenue Service. Limited Liability Company (LLC)
Trying to use one EIN across several LLCs can cause processing delays, misapplied tax payments, and complications during an audit. Filing information returns with the wrong EIN can also trigger penalties ranging from $60 to $680 per return, with higher penalties for intentional disregard of the rules.3Internal Revenue Service. Information Return Penalties
The Single-Member LLC Exception
The one place this rule bends is for a single-member LLC that the IRS treats as a “disregarded entity” — an LLC with one owner that hasn’t elected to be taxed as a corporation. If that LLC has no employees and no excise tax liability, it doesn’t need its own EIN at all. The owner can use their Social Security Number or an existing EIN for federal income tax reporting.4Internal Revenue Service. Single Member Limited Liability Companies
Two limits on this exception are worth knowing. First, most banks will still require an EIN to open a business account, and some states require one for state tax purposes, so many single-member owners get one anyway. Second, the moment a disregarded-entity LLC hires its first employee or takes on excise tax obligations, it must obtain and use its own EIN for employment tax reporting — even though it remains disregarded for income tax purposes.4Internal Revenue Service. Single Member Limited Liability Companies
The exception does not scale up. If you own two disregarded single-member LLCs that both meet the criteria, the fact that neither one needs its own EIN doesn’t mean you can put one EIN on both — it means each can ride on your SSN or existing EIN separately. There is still no shared EIN across the LLCs themselves.
What You Can Run Under One EIN
People sometimes think they’re operating “multiple businesses” when they’re really operating one entity with multiple faces. Those situations do share an EIN, because there is only one entity involved.
DBAs and Trade Names
A “Doing Business As” name — also called a trade name or fictitious name — is not a separate legal entity. If your LLC operates several brand names, all of them fall under that single LLC and use the same EIN. Registering a new DBA does not require a new EIN.
A Sole Proprietor With Several Business Lines
A sole proprietor can run multiple unrelated business activities under one EIN. Someone who does freelance writing and also sells handmade crafts can use a single EIN for both, provided neither activity has been registered as its own LLC or corporation.5Internal Revenue Service. When to Get a New EIN Adding a new location or changing your business name also does not require a new EIN.
The dividing line is legal formation. File articles of organization for a new LLC, and you have a new taxpayer that needs its own number. Stay under an existing entity, and you don’t.
The Legal Risk of Sharing an EIN
Beyond the tax filing headaches, using one EIN for multiple LLCs can quietly undo the liability protection you formed them for. The whole point of setting up separate LLCs is to wall off each business’s debts and legal exposure from the others. Sharing tax identification numbers, commingling bank accounts, and skipping separate books blur those walls.
Courts call the resulting doctrine “piercing the corporate veil.” When an LLC is not operated as a genuinely separate entity, a judge can hold the owner personally liable for its debts. Factors courts examine include whether the business maintained its own bank accounts, kept separate books, and followed organizational formalities such as adopting an operating agreement. Small and single-member LLCs face the highest exposure. Using the correct EIN for each LLC is one of the simplest ways to keep the separation intact.
Getting the Additional EINs You Need
Form the LLC with your state before applying. The IRS notes that applying for an EIN before the entity is officially formed can delay your application.6Internal Revenue Service. Get an Employer Identification Number Once the state has processed your articles of organization, you can apply.
One scheduling constraint matters if you’re forming several LLCs at once: the IRS limits applications to one EIN per responsible party per day, regardless of how you apply.7Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025) If you need EINs for four new LLCs, that’s four separate days.
The fastest route is the IRS online EIN assistant, which issues your number immediately upon approval. The tool is available Monday through Friday from 6:00 a.m. to 1:00 a.m. the next day, Saturdays from 6:00 a.m. to 9:00 p.m., and Sundays from 6:00 p.m. to midnight, all Eastern Time.6Internal Revenue Service. Get an Employer Identification Number Fax submissions of Form SS-4 usually get a response within four business days, and mailed applications take roughly four to five weeks.8Internal Revenue Service. Instructions for Form SS-4
However you apply, the IRS mails a CP 575 confirmation notice to the address on your application. Keep each LLC’s notice with that LLC’s records; it’s the official reference for the number tied to that specific entity.