Below is a guide to submitting an application, and information to help ensure that you meet all requirements for employment with ICE. The ISSO requires submission of a job offer letter (or other proof of employment) for OPT Reporting Requests.If the individual is currently residing in the United States, he or she must complete form I1140 Immigrant Petition for Alien Workers. US work visas requires the prospective employer to first file a petition with U.S. Citizenship and Immigration Services (USCIS). You must provide proof of current income with the I864. A letter of future employment is not proof of current income. Prepare the Following Documents: 1. Form I-765 - Application for Employment Authorization - please complete it on-line, print it out and bring it with you. Dallas County employs only U.S. citizens and lawfully authorized non-U. A letter from my company, to the Dallas Local office verifying my Employment status.