Hello,
I am currently working for Company A under H1B visa. I've recently accepted an offer from Company B and they are now in the process of transferring the visa. The receipt for application of I-129 (and I-539 for my wife) should arrive in a few days. And the tranfer is done through premium processing, so it should take another 10-15 days for it to get done. Now there is another Company C from which I should be receiving an offer in a few weeks. And this is the company I want to work for. Now I understand that there is no restriction on applying for multiple transfers at the same time. Two situations here
1. When Company C is ready to file for my H1B transfer, they would be asking me for all the previous I-797's. But I would just have the receipt from Company B. So my question is can Company C file for the transfer just based on the I-129?
2. If the transfer to Company B is approved but if I dont have the I-797 from them, even then can Company C file for the transfer just based on the I-129? Or in this scenario they would need the latest I-797? Also just wondering if Company B can legally withhold the physical copy of I-797 and the whole petition with them and avoid sending it to me?
Thanks a lot for your help.

