How to Get a Tax ID Number for Your Business

If you need to learn how to get a tax ID number, there are several options. You can apply online through the Internal Revenue Service (IRS) directly or a third-party service, or fax an application using Form SS-4. International applicants can apply by phone, but if you prefer to mail in an application, that is a slower alternative.

What Is a Tax Identification Number?

A tax identification number (TIN) is a unique identifier for a person or a business. Some examples are the Social Security number for an individual (SSN), Individual Tax Identification Numbers (ITIN), and Employer Identification Numbers (EIN). People, businesses, nonprofit organizations, and other entities need a number to file taxes and other documents. To keep things consistent, all these numbers have nine digits. A TIN comes from the federal government through either the Internal Revenue Service (IRS) or the Social Security Administration (SSA).

The IRS mandates that businesses get an EIN, also called a business tax ID number. It allows the IRS to classify businesses according to the kind of goods and/or services they provide. It also gives the entity a unique piece of identifying information to use on official records.

When you're starting a new business, there are four ways to get assigned an EIN by the IRS. Two of them give you your number on the spot, so you are ready to start using it right away. Of the other two, one is only available from outside the United States, and the other takes about four weeks.

If you lose your EIN, you can call the Business & Specialty division of the IRS at 800-829-4933. You will need to give identifying information for security reasons so that your personal information stays safe.

Once an EIN is assigned, it's never canceled because the historical record needs to be maintained. Even if a business closes, the account is closed, but the number stays available for future reference.

Steps to Get a Tax ID Number

1. Decide if you really need an Employer Identification Number.

  • Any business that withholds taxes on employees' payroll needs an EIN to ensure that payments to the IRS are properly credited.
  • New businesses need an EIN to pay taxes or open business accounts or lines of credit with vendors.
  • Corporations and business partnerships must get an EIN per IRS regulations.
  • Estates, trusts, and nonprofit organizations also need an EIN.
  • Sole proprietorships don't have to get an EIN, but they can if they prefer to do business that way instead of using the owner's Social Security number. That helps keep personal and business matters separate.

2. Once you know you need an EIN, you can apply for one with the Internal Revenue Service in one of four ways: online, by fax, in the mail, or by phone (only available to businesses outside the United States). The application form is Form SS-4 if you're looking for it on the IRS website.

  • Online: This is probably the fastest and easiest way to apply from inside the United States. The person completing the application should be the person or people who are responsible for the business, like the owners or partners.
  • The tax ID number is available immediately, and the application is short, requiring only about 20 minutes. However, you must finish it in a single session, or the system will log you out if you're inactive for 15 minutes or more. Just go to and find the Employee Identification Number Assistant page to get started. The link is at the bottom. This method is available to all legally recognized business forms in the United States and its territories.
  • You can also apply online through a third-party service, EIN Filing Service, by visiting This group is not affiliated with any department of the federal government; they simply offer the service to clients for a fee. This is a secure way to apply, and someone else takes care of all the paperwork, saving you time. The online portal gathers the relevant information for accuracy. You get your number via email, and it's ready to use right away. Another copy comes in the mail later.
  • Down the road, if you need to make changes to your business information, EIN Filing Service can help with that too at no additional charge. It's easy and fast, and it's ideal for people who don't like completing paperwork.
  • Phone: Only international applicants can apply by phone. The toll-free number to the IRS for this process is 800-829-4933, and the hours of availability are 7 a.m. to 10 p.m. local time for the business. An IRS staff person will take the relevant information and give the TIN at the end of the call.
  • Fax: Another way to apply is to send an application by fax using Form SS-4. The fax number to use depends on the state where the business is; you can find them at If the applicant puts a return fax number on the form, the IRS will send the TIN in four business days.
  • Mail: You can also apply for a tax identification number via regular mail. This takes up to four weeks, so it's the slowest of the four options. The IRS returns your TIN to you in the mail.

3. The next step is choosing the right kind of EIN for the type of business you operate. Some possibilities are sole proprietorship, corporation, LLC, partnership, nonprofit, or estate.

4. You also need to state why you are applying at this time. This could be a new business, or maybe you've been operating under your personal Social Security Number and want to set up an EIN to move away from that. Your request might also be related to hiring new employees or setting up a pension plan. Finally, you need to fill in what field you're in and what products or services you offer and give your name and SSN to complete the form.

5. Once everything is complete and submitted, the new EIN appears on the screen. You can start using it right away, and you get an official letter from the IRS electronically that you can save for your records.

Finding the Federal Tax ID Number of a Third Party

If the number you are looking for is that of a business you regularly interact with, you may find it on an invoice, a receipt, or another business record. For example, day care centers often put their Employer Identification Number on forms and invoices because parents need this information for tax purposes to be able to deduct those expenses.

Nonprofit organizations often list their tax ID number on donation receipts so that the donor can take the deduction for their business or personal tax return. Some companies, especially publicly traded ones, list the EIN on their website, often on an "About Us" or "Legal Disclosures" page or something similar.

If you have to call a business to ask for the EIN, try the Accounting Department or Human Resources as they are the ones most likely to have that on file. This is more difficult if the company is out of business, but the information does still exist. Someone is still in charge of the records. You may be able to get that information from the Secretary of State's office in the state where the business operated.

If you're searching for the EIN of a publicly traded company or a nonprofit organization, there are free directories online that can help. Try EDGAR, the Electronic Data Gathering, Analysis, and Retrieval system, for publicly traded companies. It's maintained by the Securities and Exchange Commission (SEC). The EIN is also listed on the company's 8-K, 10K, or 10-Q reports. If you're looking for the EIN of a nonprofit organization, try Melissa Data.

If all these options still don't find the number you need, try the IRS directly to find the number. Use the contact information on to reach an agent. Explain why you need the number and all the things you've already attempted. The agent can help or at least make some suggestions about the next step.

As a last resort, there are attorneys and private investigators you can hire to track down the number. They have legal search engines not accessible to the general public that might be able to find the information. However, think about whether the tax deduction or whatever you need the number for is worth the cost, which is probably going to be several hundred dollars.

Finding an Individual Tax ID (SSN or ITIN)

Though there are pros and cons to doing it, if you have a Social Security number, you can use that as your tax ID, even in business. If you work for someone else as an employee, you get a W-2 no later than Jan. 31 of each year, and the SSN is there at the top. If you need a copy of a form from a previous year, you can get it from the employer who issued it. Employers must keep these for at least four years after you leave the company. Your tax return, like the 1040, the 1040A, or the 1040EZ lists your SSN at the top of the first page.

If you don't have a Social Security number, but you have filed taxes in the past, you may have used an Individual Tax Identification Number (ITIN) on the forms in the space where the SSN usually goes. That number is valid if used in 2013 or later unless the IRS has notified you that you need to renew. If you do need to renew, use form W-7 to ask for a new ITIN. That process takes about seven weeks. If you have a valid ITIN, but you cannot find it, call 1-800-908-9982 from within the United States for help.

If you lose your Social Security card, you can apply for a new one online if you have a driver's license or another form of state identification. You can also fill out a paper form and turn it in to the local Social Security Administration office; you'll need to take your birth certificate and a photo ID.

Finding the Employer ID (EIN)

If you're looking for the EIN of a business, there are several places to search.

  1. Check the W-2 form the employer sends to employees, in the top left corner. If you don't have a W-2, contact the payroll department of the business. If the employer is a publicly traded company, visit the company's website and look under SEC filings. The most recent quarterly report or SEC filing report usually lists the Employer Identification Number near the top of the first page. No matter the type of business, tax documents should have the EIN, usually at the top of the first page.
  2. If you are the owner of a business and you used the EIN to open a bank account, the bank will have it on file. The EIN of a business may change if the company goes through bankruptcy, changes owners, incorporates, or merges. Forms from a date prior to a major event like that may not contain correct information.
  3. If the owner of the business held a license or permit for his business through the city, county, or state, contact the business services office of that governmental entity for help.
  4. You can call the Internal Revenue Service directly at (800) 829-4933. That gets you to the Business & Specialty department. They can help you find a lost number of your own using the company's name, title, and Social Security number. This line is open from 7 a.m. to 7 p.m. in the local time zone, Monday through Friday.
  5. When a business first applies for an EIN, if they apply online, they get an electronic response letter with the number on it. Check the business email to see if it is still there.
  6. If the business changes hands, the new owners probably want to get a new EIN. Use Form SS4 and send it via mail to the IRS.

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