If there's one piece of financial advice you should follow, it's this one: never cosign anything. I don't care if your best friend since you were seven wants to live in a one-bedroom apartment they claim they can afford but don't make 20 times the annual rent. I don't care if your brother has finally gotten back on his feet and needs a car to get to his job in the city. I really don't care if your kid sister, who is still in grad school, really wants to buy a house near her parents but can't afford it on her own. There are very few good reasons for taking responsibility for debt that's not your own. It's stressful enough to pay off your own credit card and student loans, but to assume full financial responsibility for someone who isn't your kid is not very financially sound, at least if you want to keep your money in your bank account.