H1B transfer and getting 3 years H1B extension based on approved 140 from current employer

[a100]

Hi,

Currently I am working with company A and my I-140 is approved and I am in 6th year. I am planing to join company B. The new company B will be applying for H1 transfer and get 3 years extension (I-797) based on approved I-140 from current employer.

I do not have I-140 approval copy but I do have receipt number. The new company B is saying that they need I-140 approval copy to transfer my visa on their name (because they may receive RFE for I-140 approval copy).

Does company B need I-140 approval copy to successfully transfer H1B and get 3 years extension or only receipt number is enough to transfer H1B and get 3 years extension.

Thank you.