H4 just approved, and got a job offer

[pqpq0101]

Hello,

After being let go in November while working on an H1B visa, I had applied for change of status to O3 dependent visa. The case status on USCIS says -

"On January 10, 2011, we mailed you a notice that we have approved this I539 APPLICATION TO EXTEND OR CHANGE NONIMMIGRANT STATUS. Please follow any instructions on the notice."

Also, I just got a job offer this week. Although I'm yet to talk to the new company lawyer, I was curious to know if I can file for another change of status application before I actually have the O3 petition acceptance I539 in my hand? Also, once I file the H1B application, do I again have to wait for it's approval to come through or can I start working as soon as I receive the acknowledgment receipt.

Many many thanks for your help!

[kabkaba]

You will need the COS approval notice with I-94 in order to apply for any further COS.
COS to H1 is filed as part of H1 petition by your employer. You have to wait for approval of this to start working (unless you are in H1 status which you are not). With premium processing you can receive a decision in 15 days.

[pqpq0101]

Thank you, kabkaba.