Banks offered two essential sources of finance to trade and commerce. First, the merchant banks financed trade through the bill of exchange, which banks would discount for exporters so they received payment on shipping the goods. From the middle of the nineteenth century the bill of exchange might be drawn under a letter of credit issued by the importer’s bank and payable on presentation of the shipping documents, notable the bill of lading which gave title to the goods. Second, banks provided working capital to industry – not long-term finance - enabling it to pay wages and the cost of raw materials in anticipation of the sale of finished products in home and export markets. This was done by means of an overdraft on the customer’s account (who could draw up to that amount) or through a short-term loan. Typically, both were repayable on demand. They might be unsecured, or supported by a personal guarantee, but in some cases the customers had to provide collateral. Underpinning the banks’ performance in both areas were sophisticated institutional arrangements such as the bankers’ clearing house and the money markets. All these arrangements operated within a framework of generally supportive law.