Federal Tax ID Number for a Business: What It Is and How to Get One

Tax ID, EIN, TIN, FEIN: which is which

The vocabulary is the confusing part, so here it is in one place. A taxpayer identification number (TIN) is the umbrella term for any number the IRS uses to identify a taxpayer. An SSN is a TIN for a person. An ITIN is a TIN for a person who cannot get an SSN. An EIN, also written FEIN for Federal Employer Identification Number, is the TIN for a business, trust, estate or nonprofit. When a form, a bank or a customer asks for your business’s “tax ID number,” “federal tax ID,” “federal ID number” or “employer ID,” they all mean the EIN. The EIN vs TIN vs SSN guide goes deeper.

Which businesses need their own number

• Corporations, including S corporations: always.
• Partnerships and multi-member LLCs: always, because the partnership return is filed under it.
• Any business with employees, including a single owner on payroll: always.
• Trusts, estates and nonprofits: always, once they hold an account or file a return.
• Single-member LLCs and sole proprietors with no employees: not required by the IRS, but required by nearly every bank to open a business account, and by most payment processors and lenders.

The do-I-need-an-EIN guide has the IRS rule in full, and the LLC guide covers the case that comes up most.

What the number looks like and where it appears

Nine digits with a hyphen after the second: 12-3456789. The first two digits used to indicate the IRS office that issued it; they no longer carry meaning. It appears on the CP 575 notice the IRS sends when the number is assigned, on every federal business return, in box b of the W-2s you issue, on the W-9 you hand to customers, and in your bank and payroll records. It never changes and never expires.

How to get a tax ID number for a business: the four steps

1. Form the entity first if it is an LLC or corporation. The IRS wants the legal name and formation date exactly as the state recorded them.
2. Gather the facts the application asks for: legal name, physical address, entity type, number of members or owners, the responsible party’s name and SSN or ITIN, what the business does, and the date it started.
3. Apply by one of four routes. The IRS online tool is fastest when it accepts the application; it is open Monday to Friday 6 a.m. to 1 a.m. (into the next day), Saturday 6 a.m. to 9 p.m., and Sunday 6 p.m. to midnight, Eastern time, issues one number per responsible party per day, and must be finished in one sitting. Fax takes about 11 business days, mail takes weeks, and the international phone line is for businesses with no US address. The how-to-get-an-EIN guide walks through each.
4. Save the confirmation notice, the CP 575. The IRS issues it once and banks ask for it.

How to obtain a business tax ID when the online tool will not issue one

The online application only works for a responsible party with an SSN or ITIN, during its posted hours, once per responsible party per day, and only when the IRS finds no conflict with the business name. Outside those conditions the route is Form SS-4 by fax, with the state formation certificate attached if the name was the problem. The number comes back by fax in about 11 business days when a return fax number is on the form, or by mail in about four weeks when it is not. Preparing and filing that form, and dealing with whatever the IRS sends back, is the service we sell.

The numbers that are not a federal tax ID

Three other numbers get mistaken for it. The state entity or filing number the Secretary of State stamped on your formation documents identifies the company in state records only. A state tax ID is a sales tax permit, withholding account or unemployment insurance number issued by the state revenue agency after you register, and one business can have several. A DUNS number is a private identifier from Dun and Bradstreet used for business credit and federal contracting. None of them can be used where an EIN is asked for. The state tax ID vs federal EIN guide sorts out the state ones.

Quick answers

Is a federal tax ID number the same as an EIN?

Yes. Same number, different name. FEIN, federal ID number and employer ID number are also the same thing.

Can I use my SSN as my business tax ID?

For federal tax purposes, a sole proprietor or single-member LLC with no employees can. For a business bank account, a merchant account or a business loan, almost never; those want the entity’s own number.

How long does it take to get one?

Minutes through the IRS online tool when the application is accepted, a few business days by fax, and several weeks by mail. The timing guide has the details and the delays.

I already have one and cannot find it. Do I apply again?

No. Applying again creates a second number for the same business, which the IRS then has to close. Retrieve the existing one; the lookup guide lists where it is written down and how to get a 147C letter.