Contact your intergroup/service board. They may have a tax ID that covers all the affiliated groups. If not, your U.S. group must apply for one with the Internal Revenue Service (IRS). The required form is SS-4, Application for Employer Identification Number. You can print out a form at http://www.irs.gov/pub/irs-pdf/fss4.pdf. You can also apply online at https://sa2.www4.irs.gov/modiein/individual/index.jsp. When asked for the type of business, select other and write in “volunteer group,” or view additional types and select community or volunteer group if applying online. The remainder of the form is straightforward.