What should I know before co-signing someone's loan?

Co-signing means you are equally responsible for the debt, not just a backup. If the primary borrower misses payments, the lender will come after you, and your credit score will take the hit just as hard as theirs. The full loan amount counts against your debt-to-income ratio, which can affect your ability to get your own loans or mortgage. Before agreeing, make sure you fully trust the borrower's financial habits and have seen their budget. Understand that you may have little control over whether they pay on time. Ask whether the lender will notify you if a payment is missed. Only co-sign if you are genuinely prepared to make the payments yourself, because there is a real chance you will have to.