<prompt> Human: Probably preaching to the choir here, but:About 10 years ago my best friend called me up. Hed graduated from an expensive private school with 100k in student loan debt, and had been admitted to law school at the same place. Turned out he was having a wee bit of trouble financing it. He wanted to know if Id co-sign on a law school loan or two.At the time, I didnt even know what that meant I got through college with no debt, thank the Old Gods. Called up my dad who strenuously advised me to under NO circumstances co-sign on anyone elses loan, ever. So I told my buddy sorry, but no. Unfortunately, our friendship was never the same after that. Im sure he resented me for not being a true bud and signing. But somehow or other he managed to get financing for God knows how many more tens of thousands in loans for law school.Fast forward 10 years. Found out recently that, like many with law degrees in the current economy, his income hasnt kept pace with his loans, and hes defaulted on his student loans and the debt collectors are pounding on his door, taking his car, garnishing wages, taking out liens, etc. And if I had agreed to co-sign those years ago, those debt collectors would be coming after me. Thank the Old Gods for my dads wise advice, and the lesson is: never, ever co-sign. Ever. EDIT: Interesting minority of folks here chiming in to say they co-signed X loan with no problems. Some get lucky, I guess. Also, I suppose that in a very few limited number of situations - parents helping children - co-signing might make sense. I still wouldnt do it if it could at all be avoided, though.EDIT 2: So many horror stories. Anyone considering co-signing a loan should be required to read through these comments first.  <response>: Your friend wasnt much of a friend by asking you to co-sign his law-school loans in the first place. I know I wouldnt saddle any of my friends with that kind of financial responsibility. You wouldve entered into an arrangement where there was zero upside for you but plenty of potential downside. Props to you for turning him down. 