Co-signing on someone else's private student loan isn't a decision to make lightly.
While parents represent three-quarters of co-signers, it's not unusual to see others pitching in, according to a new report from private loan marketplace Credible.com, which assessed nearly 8,000 borrowers who requested a quote through the platform. Among loans with co-signers, 3 percent used a sibling, 11 percent another relative, and 2 percent a friend.
Having someone else lend their good credit can yield more affordable loans. Only 20 percent of undergrads applying on their own qualified for a personalized rate quote, Credible found, and they got an average loan rate of 7.46 percent. (Some offers were for fixed-rate loans, others, variable rates.) When undergrads applied with a co-signer, 51 percent qualified, and the average loan rate on offer was 5.37 percent.