What a Tax ID Number Is and Who Needs One
A Tax ID Number (also called an Employer Identification Number or EIN) is a nine-digit code the IRS uses to identify your business, nonprofit, or other entity for tax purposes. You need one if you operate a business, hire employees, file certain tax forms, or run a nonprofit. If you are self-employed and have no employees, you may use your Social Security Number instead, but many self-employed people get an EIN anyway to keep business and personal finances separate.
The IRS issues Tax ID Numbers free of charge. You do not pay a fee to obtain one, and you do not need to hire a tax professional to get it — though you can if you prefer. The process takes minutes if you apply online, or a few weeks if you apply by mail or phone.
Key Takeaways
- You can get a Tax ID Number free from the IRS online at irs.gov/ein, by phone at 1-800-829-4933, or by mailing Form SS-4 to your regional IRS office.
- Online applications are approved instantly and you receive your number the same day; phone and mail applications take one to four weeks.
- You will need your Social Security Number, business name, business address, and the date you started or plan to start your business.
- A Tax ID Number is permanent and does not expire, even if your business closes — you do not need to renew it.
Three Ways to Apply for a Tax ID Number
The IRS offers three routes: online (fastest), by phone, or by mail. Online is the simplest if you have internet access and can apply during business hours (Monday through Friday, 7 a.m. to 10 p.m. Eastern Time).
Online application: Go to irs.gov/ein and select "Apply for an EIN Online." Answer questions about your business type, ownership structure, and reason for needing the number. The system asks for your Social Security Number, business name, business address, and the date you started or plan to start operations. You receive your Tax ID Number instantly on screen and by email. This route works for most business types and is free.
Phone application: Call the IRS at 1-800-829-4933 during business hours. A representative walks you through the same questions as the online form. You receive your number by phone immediately and by mail within two weeks. This route works well if you prefer speaking to a person or do not have reliable internet.
Mail application: Download Form SS-4 from irs.gov, fill it out by hand or type it, and mail it to the IRS office for your state. Processing takes two to four weeks. Include your Social Security Number, business name, business address, and the date you started or plan to start. Mail this route only if you cannot use online or phone — it is slower and you have no confirmation until the IRS responds.
Documents and Information You Will Need
Before you start, gather these items. You do not need to print or mail anything for online or phone applications — you just need the information on hand.
| Information Needed | Why the IRS Asks |
|---|---|
| Your Social Security Number | Identifies you as the owner or responsible party for the business. |
| Business name (exactly as it appears on your business registration or license) | The IRS matches this to state records to verify your business exists. |
| Business address (physical location, not a P.O. box) | The IRS uses this to route mail and verify your business location. |
| Date you started or plan to start the business | Determines when your Tax ID Number becomes active for tax purposes. |
| Business structure (sole proprietorship, partnership, LLC, corporation, nonprofit, etc.) | Determines which tax forms you will file and how the IRS tracks your business. |
| Reason for needing the number (hiring employees, opening a bank account, filing taxes, etc.) | Helps the IRS route your number to the correct department and flag any special requirements. |
If you do not yet have a business address, you can use your home address. If you are applying on behalf of a business you do not own (for example, as a manager or accountant), you will need written authorization from the owner.
How Long It Takes and When You Can Use Your Number
The timeline depends on which method you choose. Online applications are the fastest: you receive your Tax ID Number on screen immediately and can use it right away. The IRS also emails a confirmation, which arrives within minutes.
Phone applications are also fast. You receive your number by phone at the end of the call and can use it immediately. The IRS mails a formal confirmation letter within two weeks, but you do not need to wait for it — the number is active as soon as you receive it by phone.
Mail applications are slowest. The IRS typically processes Form SS-4 within two to four weeks. You receive your Tax ID Number and a confirmation letter by mail. Do not use the number for any purpose until you receive the official letter, because the IRS may not have processed your application yet.
Once you have your Tax ID Number, it is permanent. It does not expire, and you do not need to renew it even if your business closes or changes structure. If your business closes, you may need to file a final tax return, but you do not surrender or cancel the number itself.
Special Situations: Nonprofits, Trusts, and Partnerships
Most businesses follow the standard process above, but some structures have additional requirements. Nonprofits must provide proof of tax-exempt status or a copy of their articles of incorporation. Trusts must provide the trust document or a certification of trust. Partnerships must provide the partnership agreement or a statement signed by all partners confirming the partnership exists.
If you are applying for a nonprofit, you may also need to file Form 1023 or Form 1023-EZ with the IRS to obtain tax-exempt status. A Tax ID Number is separate from tax-exempt status — you get the number first, then file for exemption. Some nonprofits get a Tax ID Number before they are officially recognized as tax-exempt, and that is normal.
If you are unsure whether your business structure requires extra documentation, call the IRS at 1-800-829-4933 before you apply. A representative can tell you what to submit.
What Happens After You Receive Your Tax ID Number
Once you have your Tax ID Number, use it on all business documents: bank accounts, tax forms, contracts, and payroll records. If you hire employees, you must use your Tax ID Number on their W-2 forms and payroll tax filings. If you file business income tax returns, the number goes on those forms too.
Keep your Tax ID Number and the IRS confirmation letter in a safe place. You will need them to open a business bank account, file taxes, and respond to any IRS correspondence. If you lose the number, you do not need to apply again — the IRS has a record of it and can provide it if you call 1-800-829-4933 with your business name and Social Security Number.
Frequently Asked Questions
Can I get a Tax ID Number if I do not have a business yet?
Yes. You can apply before you officially start operations. On the application, enter the date you plan to start the business. The IRS will issue the number, and it becomes active on that date. This is useful if you need the number to open a business bank account or sign a lease before you officially launch.
Do I need a Tax ID Number if I am self-employed with no employees?
No, you can use your Social Security Number on your tax return instead. However, many self-employed people get a Tax ID Number anyway to keep business and personal finances separate and to make it easier to hire employees later without applying again.
What if I already have a Tax ID Number and need a replacement letter?
Call the IRS at 1-800-829-4933 or visit irs.gov/ein. You can request a replacement confirmation letter without applying again. The IRS will mail it to you within two weeks. You do not need to provide the original number if you have your business name and Social Security Number.
Can someone else apply for a Tax ID Number on my behalf?
Yes, if you give them written authorization. They will need your Social Security Number and business information. Many accountants and business formation services apply for Tax ID Numbers on behalf of their clients. Make sure you trust the person, because they will have access to your business tax information.
Is there a fee to get a Tax ID Number?
No. The IRS issues Tax ID Numbers free of charge. If someone charges you a fee to obtain one, they are overcharging you for a service you can do yourself at no cost. The only exception is if you hire an accountant or lawyer to handle the application as part of broader business setup services.