H1B to H4 COS filed, got a new job

[sash2]

I was working for employer A on H1b visa and left the job on Sep 15, 2017 to join my husband who got a job at a different location. My previous employer didn't revoke my H1B visa and I have filed H1b to H4 COS application before last day on my job. The application has been received by USCIS. After that, I haven't received any further communication. Now, I've got a new job and the employer B is willing to sponsor H1B visa in premium processing. I am good with that but not clear about the entire process. I want to ensure that I stay in legal status all the time so that there is no impact on any future applications that I file with USCIS.

It would be great if some one could advise about the entire process. To be more specific though:

1. Would the new employer file COS from H4 to H1B or from H1 to H1?
2. Irrespective of how it is filed, can I start working immediately as soon as petition is approved or do I need to get the stamping done before starting to work?
3. If the new H1B petition gets approved and H1 to H4 is still pending, what would be my status from last day of my work until new petition is approved? 4. Do I need to withdraw H1 to H4 COS application if the H1 petition filed by new employer is approved or it will be automatically considered abandoned?

[visaseekerUS]

If you have not received H4 COS yet, you can do h1 transfer in premium and start working after you receive H1 transfer. Once H1 transfer is approved you can revoke H4 COS.

[pontevecchio]

Your best bet is to wait for H1 petition approval and then leave and return with the H1 visa.

[sash2]

@pontevecchio - Thanks for your reply. Couple of additional questions:

1. What would be my status from the last day of my job until I travel out of country and come back with stamped visa? My understanding is that if I travel out of country then H4 COS application would be abandoned. In that case would I be in legal status for the period mentioned above?

2. Why is travel outside country needed if H1b petition is approved? Can’t I just withdraw H4 application?