We are pleased to offer you the position of (title) at an annual salary of (amount) at the Wharton School of the University of Pennsylvania. Jefferson works with outside immigration counsel to prepare and submit H-1B petitions.Typical preparation and processing time for a new petition is 180 days. What does the immigration petition process look like? It is most likely a scam. As part of the interview I need to share a job offer letter. My employer wants to write it but needs to know what all should go inside the letter. What employers need to know about H-1B visa process for employees. How to obtain H1-B visa for employees, specialized positions. TN Employment Letter.