So the SEC's EDGAR (Electronic Data Gathering, Analysis, and Retrieval) database is a good place to look in order to find free public information on these companies. A company's filings on EDGAR will likely include its EIN (or IRS number).

The IRS doesn't provide a public database you can use to look up EIN numbers for your own company or others. However, you can look at your EIN confirmation letter or other places your number may be recorded, including previously filed tax returns or old financing documents.

You may apply for an EIN online if your principal business is located in the United States or U.S. Territories. The person applying online must have a valid Taxpayer Identification Number (SSN, ITIN, EIN). You are limited to one EIN per responsible party per day.

Call the IRS to locate your EIN If you can't find your EIN in your files, call the IRS's Business and Specialty Tax Line at 800-829-4933. The line is open Monday through Friday from 7 a.m. to 7 p.m. local time.