The mortgage lender is the bank or financial entity that loans money to the person buying the home. Many buyers rely on mortgage lenders for the cash that allows them to complete the deal. Without the approval of a mortgage lender, many people are unable to follow through with a purchase. The mortgage lender is important to both the buyer and seller. For the buyer, getting approval from a lender is an important step in making a final offer on a home. The mortgage lender's pre-approval letter is an important document that gives the buyer some legitimacy in the eyes of the seller. The lender conducts a pre-approval process to determine whether the buyer has the right credentials to eventually land the loan. Without this stamp of approval, many sellers will refuse to consider the initial offer of a buyer.