NBIB creds - switch sponsors?

Curious how it works if you currently contract with one contractor (contractor A) and have your creds issued through them but want to work for another contractor (contractor B). If I am working for both on the NBIB contract but then quit contractor A, (through which my credentials are issued) what happens to my creds? Does NBIB take them back and reissue through contractor B? Sorry - obviously new to this. Is there a way to request a transfer of credential sponsors in advance? Any non-snarky advice is greatly appreciated.

You will return the creds through the losing contractor then have them reissued through the gaining contractor.