You're officially in default when you fail to meet the terms of your loan or credit agreement—usually by missing payments for a specific period (often 30-90 days, depending on the lender). Default is more than just being late; it's crossing a line that triggers serious consequences like damage to your credit score, potential legal action, or asset seizure. The good news? Default doesn't happen overnight, which means you have time to communicate with your lender and explore options before reaching this point.