I got 2 separate letters one is I821D and the second is I765 they came in two separate days from each others. My EAD card came the 3 days after I received the i765. I went to SS office the next day, I got there around 10am i filled out a form that is for when you applying for the first time for SSN, waited about 30 mn then the clerk called my number, she only ask me for ID I gave her my EAD card and passport. She never ask for my birth certificate or prove of address. She typed all info to the computer made copies of my ID's and handed a printed paper that's say they couldn't find my info in the system they have to investigate with immigration and should take around up to 4 weeks. Am taking God it's been a blessing. Hope this will help you. Good luck,