All business entities who hire employees are required to obtain an Employer Identification Number (EIN) and even sole proprietors may choose to apply for one. An EIN consists of nine digits and can be obtained online or in person. Its role is to identify a business to the IRS for tax purposes. Non-employers who form a partnership or operate as a corporation need an EIN, too.

In case you need lost your EIN or you want to find a company's EIN number, there are a couple of steps you can take. Contact the IRS by calling their tax line for businesses at (800) 829-4933, get in touch with a lawyer or look up your tax ID online. Another option is to check your bank statements and tax returns. Also, there are various online directories and databases that provide this information.

Check with the IRS

If you're searching for your own EIN, contact the IRS via their Business & Specialty Tax Line at (800) 829-4933. This service is available from 7 a.m. to 7 p.m., Monday through Friday. Only authorized persons can request this information.

For example, if you run a business and need your EIN, the IRS will help you find it. The same goes for corporate officers, partners in a partnership and persons with power of attorney. However, you cannot request another company’s EIN.

Check Your Tax Returns and Bank Statements

Unless your business is new, chances are you can find its EIN on previously filed tax returns and bank statements. Make sure you also check the original notice issued by the IRS when you applied for an EIN. If you have a license for your business, you could find this information there.

Go Online

The EIN is often listed on the company's website. If you want to check a corporation or business partner, visit their About page, their Privacy Policy page or their TOS page. This is where most companies display their EIN along with other information, such as their phone number and physical address.

You may also check your state's website to find an entity's EIN. For example, the state of Florida has an online database where users can search for local businesses by name, EIN, zip code, registration number and other criteria.

Another alternative is to subscribe to online commercial databases. These services charge a monthly or annual fee and provide information that is not otherwise available to the public, such as a company's EIN and annual revenue. EIN Finder, TIN Check and ALM Intelligence are just a few examples.

Hire a Private Investigator

If none of these options help, consider hiring a private investigator. Those who work in this industry have access to private records and know what to look for. They can help you find a corporation's EIN number or locate companies that vanished after raising funds or scamming their customers.