When you co-sign a loan or a mortgage, it is important to remember that you are taking on the responsibility of paying back the loan with the primary borrower. Your credit score will be directly affected if any payments are missed or if the primary borrower defaults on the loan. This means that in addition to making sure that payment deadlines are met and ensuring that all loans terms are followed, you could potentially have to pay off the entire amount of the loan yourself. Before agreeing to co-sign a loan, think carefully about whether this is something you can truly handle and make sure your decision is an informed one. Taking on such a large financial commitment should not be taken lightly and should be done only after thorough consideration.