Do I Need a TIN for My LLC? When an EIN Is Required and How to Apply

Yes, in almost every case you need a Tax Identification Number for your LLC, and for an LLC that number is an Employer Identification Number from the IRS. Federal law requires an EIN if your LLC has more than one member, hires employees, owes excise taxes, withholds tax on payments to non-resident aliens, or sets up a qualified retirement plan. A single-member LLC with none of those features can technically use the owner’s Social Security Number, but banks, clients, and vendors usually push you toward an EIN anyway. The application is free and takes about ten minutes online.

When Federal Law Requires an EIN

26 U.S.C. § 6109 requires any person or entity filing a federal tax return to include a taxpayer identifying number.1Office of the Law Revision Counsel. 26 USC 6109 – Identifying Numbers The regulation at 26 CFR § 301.6109-1 fills in who must furnish which number.2eCFR. 26 CFR 301.6109-1 – Identifying Numbers For an LLC, an EIN is required in any of these situations:

If none of those apply and you’re the only member, federal law lets you use your SSN. That option exists on paper. Whether it works in practice is the next question.

Single-Member LLCs and the SSN Option

The IRS treats a single-member LLC as a “disregarded entity” for income tax, which means it looks through the LLC and treats the income as yours personally. Under that classification, a single-member LLC with no employees and no excise tax liability doesn’t need its own EIN. You report the income on Schedule C using your SSN.5Internal Revenue Service. Single Member Limited Liability Companies

That arrangement is fragile. Hire one employee and you need an EIN. Take on an excise tax obligation and you need an EIN. And for employment tax purposes, the IRS treats a single-member LLC as a separate entity regardless of its disregarded status for income tax.6Internal Revenue Service. LLC Filing as a Corporation or Partnership

There’s also a privacy cost to using your SSN. Without an EIN, your Social Security Number goes on every W-9 you send to a client, every bank account application, and every vendor form. An EIN keeps that number off those documents. The IRS charges nothing for an EIN and the online application takes minutes, so most single-member owners get one at formation and never look back.

Why Banks and Clients Push You Toward an EIN

Banks ask for an EIN because federal anti-money-laundering rules make them. The Bank Secrecy Act’s customer identification program requires banks to obtain a taxpayer identification number from every U.S. person or entity opening an account.7eCFR. 31 CFR 1020.220 – Customer Identification Program Requirements for Banks For an LLC, that number is an EIN. Expect to also produce formation documents, an operating agreement, and ID for anyone authorized on the account.

Clients and vendors have their own reason. Anyone who pays your LLC $600 or more in a year generally has to report the payment to the IRS on Form 1099-NEC, and they need your TIN to do it.8Internal Revenue Service. Instructions for Forms 1099-MISC and 1099-NEC If you don’t provide a valid TIN, the payer may have to hold back a portion of your payment as backup withholding and send it to the IRS. Many businesses simply won’t hire an LLC that can’t hand over a working EIN.

What It Costs to Skip It or Get It Wrong

Missing or incorrect TINs on required filings carry per-return penalties, adjusted for inflation each year. For returns due in 2026:9Internal Revenue Service. Information Return Penalties

  • Filed up to 30 days late: $60 per return
  • Filed 31 days late through August 1: $130 per return
  • Filed after August 1 or not filed at all: $340 per return
  • Intentional disregard: $680 per return

The penalty is per return. An LLC that sends dozens of 1099s with a bad TIN can rack up serious dollars. The IRS recognizes reasonable-cause exceptions, but not getting around to applying for an EIN isn’t one of them.

How to Apply for an EIN

Online

The IRS online EIN application at irs.gov is the fastest route. You answer a series of questions and the system assigns your EIN at the end of the session. The tool runs Monday through Friday from 6:00 a.m. to 1:00 a.m. Eastern, Saturday from 6:00 a.m. to 9:00 p.m., and Sunday from 6:00 p.m. to midnight.4Internal Revenue Service. Get an Employer Identification Number One EIN per responsible party per day.

To use the online tool, your LLC’s principal place of business must be in the United States or a U.S. territory, and the responsible party must have an SSN or ITIN. If either condition isn’t met, you apply by phone, fax, or mail.

Fax or Mail

Both use Form SS-4.10Internal Revenue Service. About Form SS-4, Application for Employer Identification Number (EIN) Faxed applications typically produce an EIN within four business days. Mailed applications take roughly four to five weeks, so plan ahead if a bank deadline or client onboarding is driving the timeline.11Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025)

However you apply, the IRS mails a CP 575 confirmation notice to the address on file. That letter is your official proof the EIN was assigned, and it’s only sent once. Keep it somewhere you’ll find it later, because banks and vendors sometimes want to see it.

From Outside the United States

If neither you nor your LLC has a principal place of business in the U.S. or a U.S. territory, the online tool won’t work for you. International applicants can call 267-941-1099 (not toll-free) Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern, or send Form SS-4 by fax to 304-707-9471, or by mail to Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999.11Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025) If the responsible party has no SSN or ITIN and can’t get one, enter “foreign” or “N/A” on line 7b. Don’t leave it blank.

Information to Have Ready

Before you start:

  • The legal name of the LLC, matching your state formation documents exactly.11Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025)
  • A physical street address. P.O. boxes aren’t accepted for the street address field, though you can list one as a separate mailing address.
  • The responsible party’s full legal name and SSN or ITIN. This is one individual who controls or manages the LLC.
  • Your reason for applying (starting a new business, hiring employees, opening a bank account, and so on).
  • Entity type. You’ll select “Limited Liability Company” and give the number of members.

When You’ll Need a New EIN Later

An EIN doesn’t automatically carry over through every structural change. The IRS requires a new one when you dissolve the LLC and form a new corporation or partnership in its place, or when a single-member LLC that previously used its owner’s EIN starts filing excise or employment tax returns.12Internal Revenue Service. When to Get a New EIN

Several changes don’t require a new EIN: converting a partnership into an LLC still taxed as a partnership, electing to be taxed as a corporation or S corporation, and a single-member LLC continuing to use the owner’s existing EIN when it hasn’t elected corporate taxation and has no employees or excise obligations. Using the wrong EIN on a return causes processing delays and mismatches in IRS records, so if your situation is changing, check the IRS’s “When to Get a New EIN” guidance before you file.

A Federal EIN Isn’t a State Tax Registration

Getting an EIN handles the federal side only. It doesn’t register your LLC with any state tax agency. Most states require separate registration for state income tax withholding, sales tax collection, unemployment insurance, and other obligations, and some states issue their own state-level tax identification numbers. After your federal EIN is in hand, check with your state’s department of revenue or taxation so you’re set up for every tax your LLC has to collect or pay.