I was working on H1 from Jun 2006 Until Aug 2008. I converted to a H4 for an extended maternity leave and now I have got a job offer. I have applied for a H4 to H1 Conversion and need to know if I can start working on receipt of the application or do I need to wait until the actual approval?My H1 is valid until Sep 30 2010 and my 6 year quota has not expired. My new job offer requires me to start on 7th Sep 2010. Petition is being filed via premium processing. Presently waiting to hear back on my LCA. Thanks for the quick response Elizabeth. I am not doing a H1 transfer. The same employer who holds my H1B is filing for the petition for the conversion for H4-H1. Does your answer remain valid even in this case? Appreciate all your help!