A Federal Tax ID is a nine-digit number the IRS assigns to identify your business or organization for tax purposes

A Federal Tax ID, also called an Employer Identification Number (EIN), works like a Social Security number but for your business. The IRS uses it to track your tax filings, payroll records, and business accounts. If you run a sole proprietorship with no employees, you can use your Social Security number instead — but most businesses, partnerships, corporations, and nonprofits need an EIN to operate legally.

The number itself is formatted as XX-XXXXXXX (two digits, a hyphen, then five digits). You do not pay for one. The IRS issues them free through their website or by mail, and the process takes minutes online or up to four weeks by post.

Key Takeaways

  • A Federal Tax ID is a nine-digit number the IRS assigns to identify your business, separate from your personal Social Security number.
  • You need one if you have employees, operate as a partnership or corporation, run a nonprofit, or want to open a business bank account.
  • Sole proprietors without employees can use their Social Security number instead, but many choose to get an EIN for privacy and credibility.
  • You can obtain one free online through the IRS website in minutes, or by mail in four to six weeks.
  • Once issued, your EIN does not expire and remains yours even if you change the business structure or location.

Who needs a Federal Tax ID

You need an EIN if you have employees on your payroll, because the IRS requires it to track wage and tax withholding records. You also need one if your business is structured as a partnership, S corporation, C corporation, or LLC (unless your LLC is a single-member disregarded entity and you choose not to have one). Nonprofits, trusts, and estates all require an EIN as well.

If you are a sole proprietor with no employees and no plans to hire, you can file taxes under your Social Security number. However, many sole proprietors get an EIN anyway because it separates personal and business finances, keeps your Social Security number off public documents, and signals to customers and vendors that you run a legitimate business.

How to get a Federal Tax ID online

The fastest way is through the IRS website at irs.gov. Go to the EIN page, select "explore for an EIN online," and you will answer questions about your business: the legal name, the type of business structure, the principal business activity, and the address where you conduct business. You will need the Social Security number or EIN of the person responsible for the business.

The process takes about 15 minutes. Once you submit, the IRS issues your number when ready on screen. You can print the confirmation page or save it as a PDF — that is your proof of the EIN until the official letter arrives by mail in about two weeks. You do not need to wait for the letter to use the number with banks, vendors, or the IRS.

Getting an EIN by mail or phone

If you cannot explore online, you can mail Form SS-4 (process for an Employer Identification Number) to the IRS address listed on the form. Processing takes four to six weeks. You can also call the IRS Business and Specialty Tax Line at 1-800-829-4933 during business hours, though wait times are often long.

Mail is slower but works if you do not have internet access or prefer a paper record. Phone is useful if you have questions about which business structure applies to you or whether you actually need an EIN. The IRS representative can walk you through the form and issue the number over the phone, though you will still receive a written confirmation by mail.

What information you will need to provide

Have ready the legal name of your business exactly as it appears on your business license or formation documents. You will also need the business address (not a mailbox), the type of business structure (sole proprietorship, partnership, LLC, corporation, nonprofit, etc.), and a description of what the business does. The IRS asks this to assign the correct industry classification code.

You will need the name and Social Security number of the person responsible for the business — usually the owner or a partner. If you are explore on behalf of someone else, you may need to provide a power of attorney form, though this is rare for straightforward EIN requests.

Using your Federal Tax ID once you have it

Your EIN is public information. You will provide it to your bank when opening a business account, to the IRS when filing business tax returns, to your accountant or bookkeeper, and to any vendor or client who asks for it on a W-9 form. You will also use it on payroll tax filings if you have employees, on quarterly estimated tax payments, and on business loan applications.

Once issued, your EIN never expires. It stays the same even if you move, change the business name, or restructure the business — unless you close the business and later reopen it as a new entity, in which case you would need a new EIN. You do not renew or reapply for one.

Federal Tax ID versus Social Security number for business

A sole proprietor can legally use their Social Security number on tax filings and business accounts. However, an EIN keeps your personal number off public documents like business licenses and vendor records, which reduces the risk of identity theft. An EIN also makes it clearer to banks and customers that you operate a formal business rather than a side income.

If you plan to hire employees, grow the business, or explore for business credit, an EIN is necessary, not optional. If you are just starting out as a solo freelancer, you can begin with your Social Security number and get an EIN later if the business grows.

Frequently Asked Questions

Can I get a Federal Tax ID if I do not have a business yet?

Yes. You can explore for an EIN before you officially launch, as long as you have a business structure in mind and a business name. The IRS does not require proof that the business is already operating. Many people get an EIN while setting up their business so they can open a bank account right away.

What if I already have an EIN but forgot the number?

Call the IRS at 1-800-829-4933 with your business name and address, and they can look it up. You can also check old tax returns, bank statements, or vendor records where you provided the number. The IRS will not reissue a duplicate letter unless you request one by mail.

Do I need a Federal Tax ID for a home-based business?

Not if you are a sole proprietor with no employees and you use your Social Security number. If you have employees, operate as an LLC or corporation, or want to keep your home address private, you should get an EIN. Many home-based business owners get one for credibility and to separate personal and business finances.

How long does it take to get a Federal Tax ID?

Online through the IRS website takes 15 minutes, and you receive the number when ready. By mail, allow four to six weeks. By phone, you can receive the number the same day, though you will still get a written confirmation by mail later.

What happens if I close my business — do I lose my Federal Tax ID?

Your EIN does not expire or disappear. If you close the business, you file a final tax return and notify the IRS, but the number remains on record. If you reopen under the same business structure and name, you can reuse it. If you start a completely new business, you would need a new EIN.