EIN Application Guide: How to Get Your Employer Identification Number from the IRS

EIN Application Guide: How to Obtain Your Employer Identification Number

An Employer Identification Number (EIN) — also called a Federal Tax Identification Number — is a unique nine-digit number assigned by the Internal Revenue Service (IRS) to identify a business entity for tax reporting purposes. Think of it as a Social Security Number, but for your business. An EIN is required to open a business bank account, hire employees, file business tax returns, and apply for most business licenses and permits.

Who Needs an EIN?

You need an EIN if your business meets any of the following criteria:

Your business has employees (W-2 employees or payroll)
Your business operates as a corporation (C-Corp or S-Corp) or partnership
Your business files Employment, Excise, or Alcohol/Tobacco/Firearms tax returns
You withhold taxes on income, other than wages, paid to a non-resident alien
You have a Keogh plan or other qualified retirement plan
You are involved with a trust, estate, real estate mortgage investment conduit (REMIC), nonprofit organization, or farmers cooperative
You want to open a business bank account (virtually all U.S. banks require an EIN, even for single-member LLCs)

Sole proprietors with no employees and no Keogh plan can use their Social Security Number for federal tax purposes, but most still obtain an EIN to keep business and personal finances separate and to protect their SSN.

EIN Application Methods

Method 1: Online (Fastest — Immediate EIN)

The fastest way is the IRS EIN Online Assistant, available Monday through Friday, 7 a.m. to 10 p.m. Eastern time. Applicants with a valid U.S. Social Security Number (SSN) or Individual Taxpayer Identification Number (ITIN) receive their EIN immediately after completing the application. The EIN is displayed on screen and can be downloaded as a PDF confirmation letter.

Who can use: Entities whose responsible party has a U.S. SSN or ITIN
Processing time: Immediate (same session)
Cost: Free from the IRS

Method 2: Form SS-4 by Fax

Complete IRS Form SS-4 (Application for Employer Identification Number) and fax it to the appropriate IRS service center. The IRS will fax back the EIN within 4 business days if you provide a return fax number.

Who uses this: Entities that cannot apply online (e.g., certain foreign-owned entities) or prefer a paper trail
Processing time: 4 business days

Method 3: Form SS-4 by Mail

Mail a completed Form SS-4 to the IRS. This method is the slowest.

Processing time: 4–5 weeks

Method 4: Phone (International Applicants)

Foreign entities without a U.S. SSN/ITIN use the IRS international EIN line: +1-267-941-1099 (not a toll-free number). Call Monday through Friday, 6 a.m. to 11 p.m. Eastern time. An IRS representative verifies information from Form SS-4 and assigns the EIN during the call.

Foreign-Owned U.S. LLCs and EINs

Foreign nationals who own U.S. LLCs or corporations that require an EIN but do not have a U.S. Social Security Number or ITIN must apply by fax or phone (Methods 2 or 4 above). They cannot use the online tool. The IRS will assign the EIN within 4 business days by fax. CORPIUS assists foreign-owned entities with EIN applications as part of all business formation packages.

Information Required on Form SS-4

When applying, have these details ready:

Legal name of the entity
Trade name/DBA (if different)
Mailing address of the entity
Name and SSN/ITIN/EIN of the responsible party (the individual who controls or manages the entity)
Type of entity (LLC, corporation, partnership, sole proprietor, etc.)
State or country of formation
Reason for applying (started new business, hired employees, banking purpose, etc.)
Date business started or acquired
Closing month of accounting year (December for most calendar-year businesses)
Highest number of employees expected in the next 12 months
Principal business activity and product/service description

EIN Confirmation Letter (CP 575)

After receiving your EIN, the IRS sends an official confirmation letter (CP 575) by mail to the address provided on Form SS-4 within 4–5 weeks. This letter is often required by banks, state agencies, and some business partners. If you applied online and need a printed confirmation before the CP 575 arrives, you can use the EIN confirmation screen printout. If you lose your CP 575, you can request a 147C letter from the IRS by calling 1-800-829-4933.

Using Your EIN

Once obtained, your EIN is permanent — it does not expire. It is used for: federal and state tax filings; opening business bank accounts; applying for business credit; setting up payroll systems; applying for business licenses; issuing Form 1099s to contractors; and many other routine business activities. Keep your EIN confirmation letter in a safe place, as it serves as your primary proof of the number.

CORPIUS includes EIN registration with every business formation package. For foreign-owned entities requiring the phone or fax application process, we manage the entire EIN application on your behalf. Contact us to get started.