What is an EIN and why do you need it?

An Employer Identification Number (EIN) is an unique nine-digit number the IRS gives to businesses in the U.S. Think of it like a Social Security Number for your company. What do LLC services actually do? They often try to sell you on getting an EIN, but you can grab one yourself for free.

Just as you use your SSN to track income and pay taxes, a business uses an EIN to set up its own tax identity and deal with federal and state agencies. The IRS puts it this way: "An EIN is a nine-digit number assigned by the IRS to identify a business entity for tax purposes."

Anatomical breakdown of an EIN

An EIN follows a standard federal format: XX-XXXXXXX. Inc Authority and other formation services often tack EIN procurement onto their packages, but the IRS gives them out for free.

Issuing Authority. Only the Internal Revenue Service issues these. The IRS puts it simply: "EINs are issued by the IRS. There is no cost to apply for an EIN."

Permanence. Unlike business names or addresses, an EIN is permanent. Once assigned to an entity, that specific nine-digit identifier stays with the business forever. It can't be reused or reassigned to a different legal entity, even if the original business dissolves.

Identity Distinction. It keeps your personal credit and taxes separate from how the business runs.

Opening commercial bank accounts

No reputable bank will let a multi-member LLC, Corporation, or Partnership open a business checking or savings account with an owner's SSN. How to open a business bank account after forming a LLC starts with having your EIN ready.

The Banking Requirement. Banks need an official EIN and approved state formation documents to follow federal Know Your Customer (KYC) and anti-money laundering (AML) rules. The Financial Crimes Enforcement Network (FinCEN) puts it this way: "Financial institutions must verify who their business customers are, which means getting the entity's EIN."

Operating commercial revenue through a personal bank account immediately compromises corporate liability shields. Without an EIN, you can’t open a dedicated business account, so you’re stuck commingling funds. That’s a big reason courts pierce the corporate veil.

Hiring employees and managing payroll

If your enterprise plans to hire staff or independent contractors, you must have an EIN. When to form a LLC for a side hustle often coincides with when you start hiring, which requires an EIN.

Tax Withholding Mandate. You need an EIN to report federal income tax, Social Security, and Medicare taxes on IRS quarterly and annual forms like Form 941 and Form 940. The IRS puts it this way: "Employers must have an EIN to report employment taxes and file payroll tax returns."

State Compliance. You need an EIN to set up state unemployment tax insurance and state payroll withholding accounts, since state labor departments require it.

Entity tax classification & compliance

Certain business structures have to get an EIN by law to file their informational and corporate tax returns. LLC tax surprises for new owners often leave people confused about whether their entity type actually needs one.

Pass-Through & Corporate Entities. Multi-member LLCs, Partnerships, C-Corporations, and S-Corporations are legally required to have an EIN to file tax returns like Form 1065 for partnerships or Form 1120 for C-Corps.

Single-Member LLC Exceptions. You can technically use your SSN for tax filing if you're a single-member LLC with no employees. But banks and corporate vendors will still want an EIN to open business accounts and sign contracts.

Statutory Triggers. IRS rules say you need an EIN if you have employees, run as a Corporation or Partnership, file Employment or Excise tax returns, withhold taxes on income paid to a non-resident alien, or have a Keogh plan.

Protecting personal privacy

Independent contractors and sole proprietors often fill out Form W-9 to hand over their taxpayer ID numbers to clients who send out 1099s. The $199 EIN mistake every founder makes is paying for something that's free, but keeping your SSN safe is a real reason to grab an EIN.

Security Risk. Giving out your SSN on a W-9 puts you at risk for identity theft.

The EIN Solution. Using an EIN on Form W-9 instead of a SSN keeps your personal social security number away from clients, vendors, and third-party accounting systems. The Federal Trade Commission advises: "Using an EIN instead of your SSN on business documents can help protect you from identity theft."

How to obtain an EIN (avoiding third-party scams)

Third-party companies routinely exploit uninformed founders by charging $150 to $300 to obtain an EIN. The official, free protocol is simple. Form your entity with your state's Secretary of State. Access the official IRS portal at IRS.gov and search for the "Apply for an Employer Identification Number Online" tool. Complete the online assistant with your verified business details. Upon successful completion, select digital delivery to download Form CP 575 instantly as a PDF.