First of all, you should check either you can legally join to the current client or not. Most of the company has signed Non-disclosure agreement between two company. (e.g. current client and X company). There is a standard clause the client can't hire their employee within a year or two after terminate/leave the company. You will be in trouble, if such clause has been exist in the NDA.
The sponsoring company may cancel or even withdraw your H1B, if you leave the organization without prior notice before getting approval. They can just fax a letter saying that they are going to withdraw your H1B. Then you are no more H1B from such date. It will automatically cancel from such point.
If you signed any legal document, non-competent agreement or NDA with X company, then you should check with legal consultant before jumping to the client.
Last edited: 23-Apr-17 04:32 PM