Sample Clearing

So I have been doing some research in regards to sample use and clearing a sample to be used in a specific work. Just to clarify, I talking about using samples with a rap line, vocal line, or riff from some other work. My Question is, if I use a Sample that needs a license or permission to be used in a composition and I submit that track to a record label, who is usually the person responsible for getting the license or permission? Often record labels will take on the responsibility of mastering and promoting, but what about sample clearing? I would appreciate any input from anyone who has experience in these matters. Thank you