If I default on my loan, is my co-signer responsible for repaying my loan? February 24, 2020 23:07 Yes. If you default on your loan, your co-signer will be liable to pay it. Related articles If I build a good payment history for an extended period of time, can my co-signer be removed from my Refinanced Student Loan? What are the advantages and disadvantages of adding a co-signer to my loan? Why does my co-signer have to sign the agreement without seeing the rates? Do you require or accept co-signers for Student Loans? How do I add a co-signer to my loan?