h1 transfer from Company A to Company B before joining Company B

Hi,

I am working with company A and my H1B Visa is stamped. The stamp is expiring in Sep 2014. I have not travelled to US yet.

Now I have got an offer from Company B. They say that they plan to send me to US. Now my questions are:

  1. Is it possible for Company B to get the visa transferred under cap exempt?

  2. Should I get the visa transferred before I join company B?

3)Can Company A cancel my visa stamp if I leave them?

  1. Can I travel with Company A’s stamp and company B’s approved petition?
  1. Yes

  2. Yes

  3. Yes, but you can appear for visa stamping again using B’s approved petition

  4. Yes as long as A doesn’t get the visa stamp canceled and it has not expired