IRS EIN Application and Responsible Party IRS - Instructions for SS4 IRS EIN Application and Responsible Party IRS Web site http://www.irs.gov/instructions/iss4/ch01.html IRS: Instructions Form SS-4 https://www.irs.gov/instructions/iss4/ch01.html Instructions Apply for a Federal Tax ID IRS Web site Instructions for Form SS-4 (01/2011) Apply for a Federal Tax ID