A non-amortizing loan is a loan where your payments cover only interest during the loan term and you repay the full principal in one lump sum at maturity. Nothing you pay reduces the balance until the final due date. Your loan balance on day one is identical to the balance on the last day before it matures.
Non-amortizing loans go by several names depending on structure: interest-only loans, bullet loans, and balloon loans. The defining feature is always the same: the principal does not shrink until you pay it off in full.
Three distinct repayment patterns fall under the non-amortizing category.
Non-amortizing loans lower your near-term cash obligations. A property developer building a commercial building has no rental income yet. An interest-only loan lets you cover debt service with minimal outflows while construction and lease-up happen. You plan to refinance into a permanent loan or sell the asset once it generates stable cash flow.
Private equity investors use the same logic. You want capital available for operations and value creation, not for paying down debt that will be settled at exit.
An amortizing loan returns principal to the lender steadily. A non-amortizing loan holds the full principal at risk for the entire term. If your financial condition deteriorates between origination and maturity, the lender faces a large exposure that an amortizing structure would have reduced. Lenders compensate with higher interest rates. The longer the term and the larger the balloon, the wider the spread over an equivalent amortizing loan.
Everything works until maturity arrives and you cannot repay or refinance. This is called balloon risk. It destroyed many real estate investors who took non-amortizing loans in the early 2000s. When the 2008 financial crisis froze credit markets, they could not refinance at maturity, and lenders were not extending. Assets sold at forced-sale prices, and projects defaulted even when they had been generating positive cash flow throughout the loan term.
Non-amortizing loans work well when credit is available and refinancing is predictable. They become dangerous when credit conditions tighten at the worst moment.
You encounter non-amortizing structures in commercial real estate bridge financing during construction and lease-up, in municipal and government bonds where debt service aligns with future tax receipts, and in corporate bullet bonds issued to match debt repayment with an anticipated asset sale. Credit card balances function as non-amortizing debt: minimum payments cover interest without requiring any principal reduction.