have my h1b extension filed in Nov 2016 based on the I140 that was approved in the same month. However, I have not received the approval yet and based on USCIS timelines, it may take another 3-4 months in regular processing. I wish to change my employer due to better opportunity elsewhere. I have 4 payslips that have been generated so far. so, my ques is: 1. what all docs are required to file for transfer of H1b? 2. Can I do it even though I have H1b approval still in works , based on my i140 approval? 3. Is my current employer legally bound to give me i140 approval copy? What are my options to transfer my H1b