An Employer Identification Number (EIN) is a unique nine-digit number issued by the IRS to identify a business or other entity for federal tax purposes. It works like a Social Security number for your business. The format is XX-XXXXXXX. EINs are also called Federal Employer Identification Numbers (FEIN) or Federal Tax Identification Numbers.

Does a sole proprietor need an EIN?

A sole proprietor without employees is generally not required by law to have an EIN and can use their Social Security number for tax purposes. However, getting an EIN is recommended even for sole proprietors because it keeps your SSN off invoices and business documents, reduces identity theft risk, and is required by most banks to open a business bank account.

Does a single-member LLC need an EIN?

A single-member LLC without employees that is not choosing to be taxed as a corporation can use the owner's Social Security number for federal tax purposes. However, an EIN is required if the LLC has employees, files certain excise tax returns, or chooses to be taxed as a corporation or S corporation. In practice, most single-member LLCs obtain an EIN because banks typically require it to open a business bank account.

How long does it take to get an EIN?

Applying online through the IRS EIN Assistant is the fastest method — you receive your EIN immediately upon completing the application. Phone applications are also same-day. Fax applications take approximately 4 business days. Mail applications can take up to 4 weeks. The online method is only available to entities with a principal place of business in the U.S. and a responsible party with a U.S.-issued taxpayer ID.

Is it free to get an EIN?

Yes. Applying for an EIN directly through the IRS is completely free. The IRS does not charge any fee for an EIN. Be aware that third-party websites charge fees to apply on your behalf — this is unnecessary. You can apply for free at IRS.gov.

What is the difference between an EIN and a Social Security number?

A Social Security number (SSN) is a nine-digit number issued by the Social Security Administration to identify individual U.S. citizens and residents for tax and benefits purposes. An EIN is a nine-digit number issued by the IRS to identify a business entity. SSNs are personal identifiers; EINs are business identifiers. Both are used for tax reporting but are assigned by different agencies and serve different purposes.

Do I need a new EIN if I change my business name?

No. A business name change alone does not require a new EIN. You use the same EIN and notify the IRS of the name change. However, you do need a new EIN if the legal structure of your business changes — for example, if a sole proprietorship incorporates, or if a sole proprietorship takes on a partner and becomes a partnership.

Can a foreign national or non-US business get an EIN?

Yes. Foreign nationals and non-US businesses can obtain an EIN, but cannot apply online. They must apply by phone (calling the IRS International Calls line at 267-941-1099), by fax, or by mail using Form SS-4. The responsible party does not need a U.S. Social Security number to obtain an EIN, but the IRS may require additional information to verify identity.

What Is an EIN and Does Your Business Need One? (2026 Guide)