Definition
A cosigner is someone who signs a legal document, like a loan or lease, alongside another person, taking on shared responsibility. They're like a safety net, promising to pay if the primary borrower can't. This is common when someone lacks sufficient credit history or income, such as a young adult getting their first apartment or car loan. Unlike a guarantor who only steps in when the borrower defaults, a cosigner has the same legal obligations from the start. They are essentially vouching for the borrower's reliability. Think of it as a parent helping their child get a start in life.