Resigned from Employer A, got an offer from Employer B and payroll is not yet started. Employer C wants to file H1b Transfer

Hi,

Recently I got an offer from Employer B. So resigned from Employer A.
Got H1b transfer approved with Employer B and joined during last week only. However now Employer C is offering me a position and wants to file H1b Transfer.

Can Employer C file a H1b transfer without having the pay stubs from Employer B?

Your situation is not clear. Employer C will need the proof that you maintained status to file H1B transfer.