Breaking a mortgage early can incur significant penalties, typically either three months' interest or Interest Rate Differential (IRD) fees. Reasons for breaking a mortgage include financial changes, lower interest rates, job relocations, or personal circumstances like divorce. To minimize penalties, consider a variable or short-term fixed rate mortgage, prepaying when possible, and shopping around for lenders, especially smaller ones. Understanding the penalty calculations and lender policies before signing can help avoid high costs if you need to break your mortgage.