I have my I-140 approved(in my 6th year of H-1). But my employer is not handing the approval notice to me. I have both Receipt Number and my Labor number (starting with A.). I have filed FOIA to get copy of I-140 approval notice. I wanted to know 1) Can I transfer my H-1 to another employer by just giving I-140 receipt number to them? 2) Can my new employer use this number to file my GC and keeping the PD based on this number?
As long as your I-140 is not revoked BEFORE approval of H-1 extension/transfer, the receipt should be enough to get an extension with another employer. The priority date transfer is "automatic" and done at the USCIS level; that should not even need a receipt.