What a Tax ID Is and Why You Need One

A Tax ID (also called an Employer Identification Number or EIN) is a nine-digit number the IRS assigns to identify your business, nonprofit, or self-employment income for tax purposes. Think of it as a Social Security number for your business entity rather than for you as a person.

You need a Tax ID if you are self-employed, own a business with employees, operate as a partnership or corporation, or run a nonprofit. Even if you are the only person working in your business, the IRS uses this number to track your income and tax obligations. Banks also use it to open business accounts, and it appears on tax forms you file each year.

The process is free, takes about 15 minutes if you explore online, and you can use a temporary number when ready while waiting for the official one to arrive by mail.

Key Takeaways

  • You can get a Tax ID for free by explore online through the IRS website, by mail using Form SS-4, or by phone if you need it the same day.
  • Self-employed people, business owners, nonprofits, and anyone hiring employees must have a Tax ID before filing taxes or opening a business bank account.
  • The online process takes about 15 minutes and gives you a temporary number you can use right away; the official number arrives by mail in about two weeks.
  • You will need your Social Security number, business structure type (sole proprietor, LLC, corporation, etc.), and the date you started or plan to start your business.

how the process works Online (Fastest Route)

The IRS online process at irs.gov/ein is the fastest way to get a Tax ID. Go to the IRS website, find the EIN Assistant tool, and answer questions about your business structure, location, and reason for needing the number. The whole process takes 10 to 15 minutes.

You will need your Social Security number, the legal name of your business (or your name if you are self-employed), your business address, and the date you started or plan to start operations. Have these details ready before you begin. At the end of the process, the IRS gives you a temporary number on screen that you can write down and use when ready — for opening a bank account, hiring employees, or filing taxes.

The official Tax ID arrives by mail within two weeks. You do not need to wait for the paper version to start using the number the IRS gave you online.

explore by Mail or Phone If Online Is Not an Option

If you cannot explore online, you can request a Tax ID by mailing Form SS-4 (process for an Employer Identification Number) to the IRS. read the form from irs.gov, fill it out, and mail it to the address listed in the instructions — the address changes depending on your state. Processing by mail takes about four weeks.

If you need a Tax ID the same day, you can call the IRS Business and Specialty Tax Line at 1-800-829-4933. You must call during business hours (Monday through Friday, 7 a.m. to 10 p.m. Eastern time). Have your Social Security number, business information, and reason for needing the number ready. The IRS agent will give you a number over the phone, and you can use it when ready.

Phone lines are often busy, especially early in the tax year or if you are calling on a Monday. If you have time, the online route is usually faster and does not require waiting on hold.

What Information You Must Provide

Whether you explore online, by mail, or by phone, the IRS will ask for the same core information. You need your Social Security number or Individual Taxpayer Identification Number (ITIN), the legal name of your business, and your business address. If your business operates under a name different from your legal name (a "doing business as" or DBA), provide both.

You will also need to tell the IRS your business structure: sole proprietor, partnership, S corporation, C corporation, LLC, nonprofit, trust, or estate. This matters because different structures have different tax rules. If you are unsure which structure fits your situation, the IRS website has descriptions of each type, or you can ask a tax preparer or accountant.

Finally, provide the date you started your business or the date you plan to start. If you have not started yet, you can still get a Tax ID in advance — many people do this before opening a business bank account or hiring their first employee.

Using Your Tax ID Before the Official Number Arrives

The temporary number the IRS gives you online or over the phone is valid when ready. You can use it to open a business bank account, set up payroll, file taxes, or hire employees while you wait for the official number to arrive by mail. Banks and the IRS both recognize the temporary number as legitimate.

When the official Tax ID arrives in the mail, keep it in a safe place — you will need it for tax filings, loan applications, and business records. Some people photograph it or scan it for their records. You do not need to do anything with the temporary number once the official one arrives; they are the same number, just on different pieces of paper.

Tax ID vs. Social Security Number: When to Use Each

A Tax ID identifies your business; your Social Security number identifies you as a person. If you are self-employed and operate as a sole proprietor (the simplest business structure), you can use your Social Security number on some tax forms instead of getting a Tax ID. However, most banks require a Tax ID to open a business account, even for sole proprietors, so you will likely need one anyway.

If you have employees, operate as an LLC, corporation, partnership, or nonprofit, you must have a Tax ID — you cannot use your Social Security number. The IRS uses the Tax ID to track payroll taxes, business income, and other obligations that are separate from your personal taxes.

Many self-employed people get a Tax ID even when they are not required to, because it keeps their business finances separate from their personal finances and makes record-keeping clearer.

What Happens After You Get Your Tax ID

Once you have a Tax ID, you are set up to file business taxes. If you have employees, you will use the Tax ID to file payroll tax forms (Form 941 quarterly, and Form 940 annually). If you are self-employed, you will report your business income on your personal tax return using the Tax ID. Nonprofits file Form 990 using their Tax ID.

You will also use your Tax ID on business bank account applications, loan applications, and any time a vendor or contractor asks for your tax identification. Keep your Tax ID in a safe place — you will need it every year at tax time and for ongoing business operations.

If your business structure changes (for example, you convert from a sole proprietor to an LLC), you may need a new Tax ID. If you close your business, you do not need to do anything with the Tax ID — it straightforward stops being used.

Frequently Asked Questions

Do I need a Tax ID if I am self-employed and work alone?

You are not required to have one if you operate as a sole proprietor and have no employees, but most banks will not open a business account without one. Many self-employed people get a Tax ID anyway because it separates business and personal finances and makes taxes simpler to track.

How long does it take to get a Tax ID?

Online applications give you a temporary number when ready that you can use right away. The official number arrives by mail in about two weeks. If you explore by mail, allow four weeks. If you call the IRS, you get a number the same day.

What if I already have a Tax ID but forgot the number?

Call the IRS at 1-800-829-4933 with your Social Security number and business name, and they will look it up for you. You can also check old tax returns or bank statements — the Tax ID appears on both.

Can I get a Tax ID if my business has not started yet?

Yes. You can explore for a Tax ID before you officially open, which is useful if you need to open a business bank account or hire employees before your launch date. Just provide the date you plan to start operations.

Is there a fee to get a Tax ID?

No. The IRS does not charge for Tax IDs. If a website or service charges you to get one, you are being overcharged — you can always explore directly to the IRS for free.