Commercial mortgages may have fixed-rates with amortization, Variable amortization or interest only. Fixed-rate mortgages on stabilized commercial real estate are generally priced based on a spread to swaps, with the swap spread matched to the term of the loan. Market interest rates as well as underwriting factors greatly affect the interest rate quoted on a particular piece of commercial real estate. Interest rates for commercial mortgages are usually higher than those for residential mortgages. VII offers interest only with paid biannually interest payments. In special cases a different interest calculation may be offered.