H1B filing with 2 employers at a time

[AgastyaH1BQuestions]

Hi, 

I got a job with Company 'A' and I am supposed to join in few days with a FedEx tracking/Receipt number. meanwhile, I got another job with Company 'B' and I sent the documents to transfer my H1B to Company 'B' as well. 

Company B H1B filing/process will take at least 4-6 weeks. Since I already resigned from my current employer I thought of joining Company 'A' for the next 4-6 weeks and then shifting it to Company B. 

1.  Will my H1B have any complications in terms of VISA?
2.  Will Company 'B' H1B get withdraw automatically when Company 'A' H1B approves?
3. any other issues ??

Appreciate any help! Thanks in Advance 

[Zodiac System]

Every employer spends thousands of dollars on a transfer petition as an investment in the new employee and employer A will not be thrilled if you abandon him within a month of joining

Company B H1b will not get withdrawn automatically when Company A H1b approves.

[LeaveMessageH1B]

18 hours ago, AgastyaH1BQuestions said:

I am supposed to join in few days with a FedEx tracking/Receipt number

This is never a smart choice, FedEx is not USCIS.

1. You will have complication in terms of long wait time/ approval/RFE and documentation. Once you have clear approval, getting a visa stamp should be relatively easy. 

2.No