COS from H4 to H1b. Need to know when can my wife actually start working.


My wife is on H4 which is valid till March 2014. Currently she is in USA. A highly reputed company will be applying for her H1B on April 2013.

However, before she does that I would like to clarify a few points:

1. If it is put on premium processing then how long does it usually take to complete the conversion.

2. Lets say the approval is complete within a month i.e. May 2013. By when can she start working? Can she start working [b]immediately[/b]? Or does she need to wait until October 2013 to start working. I am under the impression that she really can start working immediately, but only needs to get her H1B stamped within a year or if she leaves the country. Is that true?
  1. Even after approval, the COS date will be Oct 1st 2013 if you file it with H1b petition until then her status will be H4.

  2. If approved, H1B authorizes you to start working only from Oct 1st 2013 and not anytime before that, eventhough the person is currently residing in USA and has applied for COS.

And as she has applied for COS and has got it approved, she would only require stamping if she ever goes out of teh country.

Thank you for the response Ramanan. Appreciate it!
A related question though: What happens if there is a change from L1 to H1B. Meaning a change between 2 diff types of work Visas. Does the same Oct 1st rule apply here too?