Lenders offer different mortgage rates to the same borrower based on the estimated risk that the borrower will fail to pay back their loan, a practice known as risk-based pricing. Factors that can influence a borrower's risk profile include their credit score, income, debt-to-income ratio, down payment, and the type of property they are looking to purchase. Different lenders are willing to take different levels of risk and can have varying costs to consider, leading to differences in the rates they offer. Additionally, promotional rates, marketing products, and negotiation can also impact the mortgage rate offered to a borrower. While interest rates are determined by national and world market forces, there can be significant variance in the rates offered to the same borrower by different lenders.