Employer not disclosing H1-B receipt details

I have an approved H1B. Due to internal policies, my organization is not disclosing the H1-B approval notice or receipt number. I want to travel on H-4 and then do a COS through employer B. If I call USCIS customer care and provide first name and last name, will they priovide the receipt no. What are the alternatives that I have.

That’s the reason your employer is not disclosing it to you. They don’t want you to change your H-1 employers. USCIS will not provide you any information about the receipt number.