Obtain Form SS-4 from the Internal Revenue Service. This is an application for an employer identification number, which is the same as tax ID number according the IRS. You can download the form directly from the IRS website.
Complete Form SS-4 according the attached instructions. You will need to read all the instructions carefully since there will be some sections that may or may not apply to your charity.
Submit Form SS-4 in a variety of ways. You can complete and submit the form online in one easy step, download and print the form and send to the address indicated on the form or submit it via phone or fax.
Wait for the IRS to issue your charity tax ID number or employer identification number. The quickest way to get your tax ID number is by applying online. A faxed application will take about a week for a response, and a mailed Form SS-4 should take 4 to 6 weeks to process.