user: Hello, can you tell me what co-debtor means?[NEWLINE]agent: Sure, spouse of an applicant who started an Income-Based Payment Plan Application.[NEWLINE]agent: It is noteworthy that you are not required to repay this loan by signing the borrower's IDR request.[NEWLINE]user: Can you explain more about the ones you just mentioned?[NEWLINE][BOUNDARY][NEWLINE]user: The FSA consists of the Joint Signature Code / Reference Number.[NEWLINE]agent: As requirements you need the Reference number / joint signature code.[NEWLINE]user: How do I verify the FSA?[NEWLINE]agent: You need to do an FSA verification.[NEWLINE][BOUNDARY][NEWLINE]user: What if I do not have the reference number / joint signature code?[NEWLINE]agent: If you do not have the verification elements, contact the IDR applicant.[NEWLINE]user: Can you give me the instructions to carry out such a process?