When do I notify resignation - H1B

[Kart2004]

Hi,

I got offer letter from another great company. They tell me that I can now notify my current employer about my plans to move over.

However I heard that I should not tell anything to my current employer till my H1 gets transferred to the new employer. Is this true?

When is the good time to let my current employer know that I am moving out? Can they cause any 'problems' for me?

Also, if I file for GC with my new employer, can my priority date be transfered?

 

[GotPR?]

When is the good time to let my current employer know that I am moving out? Can they cause any 'problems' for me?

After new employer filed transfer, preferrably after you got receipt, is safer.

Also, if I file for GC with my new employer, can my priority date be transfered?

If I-140 has been approved, yes.