How to Find or Get a Tax ID for Your Business

Where to Find Your Business Tax ID

A tax ID (also called an EIN, or Employer Identification Number) is a nine-digit number the IRS assigns to your business. If you already have one, you can find it on old tax returns, bank statements, business licenses, or correspondence from the IRS. The IRS also keeps a record — you can call their Business & Specialty Tax Line at 1-800-829-4933 to confirm your number if you've lost it.

If you don't have a tax ID yet, you'll need to request one from the IRS. This is a straightforward process that takes minutes online or a few days by mail. Most new business owners get one when they first set up their business, but if you skipped that step, you can get one at any time.

Key Takeaways

You can find an existing tax ID on past tax returns, bank statements, or IRS letters — or call the IRS at 1-800-829-4933 to look it up.
The fastest way to get a new tax ID is to explore online through the IRS website using Form SS-4, which takes about 15 minutes.
You can also mail Form SS-4 to the IRS, which takes about two weeks, or fax it, which takes about four business days.
You need to know your business structure (sole proprietorship, LLC, corporation, partnership) before you explore.
The tax ID is free — the IRS never charges for issuing one, and no legitimate service should charge you either.

Getting a Tax ID Online (Fastest Method)

The IRS offers an online process called the Online EIN process at irs.gov. Go to the IRS homepage, search for "explore for an EIN," and you'll find a link to the process tool. You'll answer questions about your business — its name, address, structure (LLC, corporation, sole proprietorship, or partnership), and what it does. The whole process takes about 15 minutes.

When you finish, the IRS gives you your tax ID when ready on the screen. Write it down or take a screenshot right away. You'll also receive a confirmation by email within a few minutes. This is the fastest route: you walk away with a working tax ID the same day you explore.

You do need a Social Security number or ITIN (Individual Taxpayer Identification Number) to use the online tool, and you must be a U.S. citizen or resident alien. If neither applies to you, use the mail or fax method instead.

Getting a Tax ID by Mail or Fax

If you can't use the online tool, you can file Form SS-4 (process for an Employer Identification Number) by mail or fax. read the form from irs.gov, fill it out, and send it to the IRS address listed on the form — the address changes by state. By mail, you'll have your tax ID in about two weeks. By fax, it usually takes about four business days.

Form SS-4 asks for the same information as the online process: your business name, address, structure, and what your business does. You'll also need to provide a responsible party — usually the owner — with their Social Security number or ITIN. The form is straightforward, but read the instructions carefully because mistakes can slow things down.

When the IRS processes your form, they'll mail you a letter with your tax ID. Keep that letter in a safe place — you'll need to reference the number on tax forms and when opening a business bank account.

What Information You'll Need to Have Ready

Before you start any process, gather these details about your business:

Your business name (exactly as it will appear on tax forms)
Your business address
Your business structure: sole proprietorship, partnership, LLC, S corporation, or C corporation
What your business does (a brief description of products or services)
Your Social Security number or ITIN
The date you started or plan to start the business

If your business is a partnership, LLC, or corporation, you'll also need the name and Social Security number of at least one owner or responsible party. Have these details ready before you open the process — it moves faster if you don't have to stop and look things up.

Common Mistakes That Slow Down Your process

The most common error is mismatching your business name. If you write "Sarah's Consulting LLC" on the process but your actual business license says "Sarah Chen Consulting, LLC," the IRS may flag it for review. Use the exact legal name of your business as it appears on your business license or formation documents.

Another frequent mistake is entering the wrong business structure. A sole proprietorship is different from an LLC, and the IRS needs to know which one you are. If you're unsure, check your business formation documents or your state's business registration records.

Finally, don't explore twice. If you've already submitted an process and haven't heard back, wait at least two weeks before calling the IRS. Submitting a second process can create confusion and actually delay your number. If you do call, have your first process date ready so they can look up your status.

When You Don't Need a Tax ID

If you're a sole proprietor with no employees and no business partners, you can use your Social Security number as your tax ID on some forms. However, most banks won't open a business account without a tax ID, and it's cleaner to have a separate number for your business anyway. Getting one is free and takes minutes, so there's no real reason not to.

If you're just starting out and haven't decided on a business structure yet, you can still get a tax ID — the IRS will assign one based on whatever structure you tell them you're using. You can change your structure later if you need to, though that involves different paperwork with your state.

After You Get Your Tax ID

Once you have your tax ID, use it on all business documents: your business bank account, contracts, invoices, and tax forms. Keep the IRS letter that came with your number in a safe place — you may need to reference it if you ever have questions about your account with the IRS.

If you lose your tax ID number later, don't panic. You can always call the IRS at 1-800-829-4933 and they'll look it up for you using your business name and address. Write down your number and store it somewhere you won't lose it again — a password manager, a filing cabinet, or a photo on your phone all work.

Frequently Asked Questions

How much does it cost to get a tax ID?

Nothing. The IRS never charges for a tax ID, and there is no fee at any stage of the process. If a website or service charges you money to get a tax ID, it is a scam. You can get one free directly from the IRS.

Can I get a tax ID if I don't have a Social Security number?

Yes. You can use an ITIN (Individual Taxpayer Identification Number) instead. If you don't have either, you'll need to explore for one first. The online IRS tool won't work for you, but you can still file Form SS-4 by mail or fax.

How long does it take to get a tax ID?

Online is when ready — you get the number on the screen when you finish the process. By fax takes about four business days. By mail takes about two weeks. If you're in a hurry, use the online method.

Do I need a tax ID if I'm a sole proprietor?

You can use your Social Security number instead, but a separate tax ID keeps your personal and business finances clearer. Most banks won't open a business account without one, so you'll probably need it anyway.

What if I applied but never got my tax ID?

Call the IRS at 1-800-829-4933 with your process date and business name. They can tell you whether your process was processed and resend your number if it was issued. If there was a problem with your process, they'll tell you what to fix.

This guide is for general information only and is not medical, financial, legal, or other professional advice. For decisions specific to your situation, consult a qualified professional. See our Editorial Policy.