H1 Transfer before stamping

Hi Saurabh/Everyone.

I have my H1B receipt number.

I got my H1B last year and my current company A has no project to send me Onsite, So no stamping is done yet…

Now, I am planning change my company in India itself.

My Qury: Is H1B transfer possible only with H1B Receipt number or do we need to know some more details of it for H1B transfer by other companies.
Depending on your valuable inputs/suggestions i have take decision.

Really appreciate all your inputs ASAP.