I am working with CompanyA on OPT for over a year and they have applied my H1b which is valid from Oct 1st 2013. CompanyB has now offered me a job. As this is a COS from OPT to H1b, I need to run for CompanyA to get any documents like pay stubs.
Question: Is it necessary that I need to prove USCIS that I have maintained H1 with companyA, and before applying h1b transfer with companyB?