EIN vs TIN vs FEIN: What Each One Means for Your LLC

The IRS describes a taxpayer identification number as an identification number it uses in administering the tax laws. It is issued either by the Social Security Administration (SSA) or by the IRS: a Social Security number is issued by the SSA, and all other TINs are issued by the IRS.

The IRS also issues two narrower TINs you will not need for an LLC: an adoption taxpayer identification number (ATIN) for a child in a pending U.S. adoption, and a preparer tax identification number (PTIN) for paid tax return preparers.

For a business, a request for a “federal tax ID” or a FEIN is usually a request for the EIN. The IRS says an EIN is also known as a federal tax identification number. The IRS's own pages say EIN, and FEIN is the same number under a longer name, so a form that says FEIN, EIN or federal tax ID is asking for the same business number, not three different ones.

“Tax ID” on its own is looser. A TIN can also be an SSN or an ITIN, so a form that asks for a “TIN” or “tax ID number” may accept more than one kind. The Treasury Regulation on identifying numbers sets the default: an individual required to furnish a number uses a Social Security number (or an ITIN if not eligible for one), and a person other than an individual, such as a corporation or partnership, uses an employer identification number. A sole proprietor engaged in a trade or business should use an EIN where the return or form and its instructions require it.

Read the form's instructions to see which number it wants. Which number to give a bank or vendor depends on how the LLC is taxed, as the next sections explain.

For federal income tax, the IRS treats an LLC by its number of members and any election it makes: a corporation, a partnership, or, for an LLC with one member, a “disregarded entity” whose activity is reported on its owner's return. The number the LLC uses follows from that classification.

The single-member LLC, in the IRS's own words

A single-member LLC that is a disregarded entity generally must use the owner's SSN or EIN for income tax information returns and reporting. For employment tax and certain excise taxes it is treated as a separate entity and uses its own name and EIN. The IRS also says that most new single-member LLCs classified as disregarded entities will need to obtain an EIN. Whether yours is one of the exceptions turns on your own facts, so confirm with a tax professional before you rely on the no-EIN case.

If your LLC does need one, you apply for it with the IRS. We walk through that in how to get an EIN for your LLC. For how single-member LLCs are taxed more generally, see the single-member LLC guide.

When a client or platform sends your LLC a Form W-9, Request for Taxpayer Identification Number and Certification, the number you give depends on the LLC's tax classification. For a disregarded single-member LLC owned by an individual, the IRS says the W-9 should provide the owner's SSN or EIN, not the LLC's EIN. A partnership or corporation gives its own EIN. The W-9 is also how a payer decides whether to send a 1099; see whether LLCs get a 1099.

Banks are a separate question. The IRS notes that a single-member LLC whose income is reported by its owner can still apply for an EIN to open a bank account. Each bank sets its own requirements, so ask yours what it needs. See opening an LLC bank account for what banks commonly ask for, and your operating agreement for a document some banks ask to see.

The IRS issues an EIN for free, and its own page warns that you never have to pay a fee for one. Register your LLC with its state first, then apply with the IRS using the name on your formation documents. The full process, with the questions the IRS application asks, is in our EIN guide. If you lost or forgot an EIN you already have, see how to find a lost EIN.