Most office and administrative support workers need to have at least a high school diploma, and some related experience or additional schooling is an asset. As in most industries, many secretaries and administrative assistants, bookkeeping, accounting and auditing clerks, and general office clerks are employed in wholesale trade. Most of the other administrative support workers are needed to control inventory. Shipping, receiving, and traffic clerks check the contents of all shipments, verifying condition, quantity, and sometimes shipping costs. They may use computer terminals or barcode scanners and, in small firms, may pack and unpack goods. Order clerks handle order requests from customers, or from the firm's regional branch offices in the case of a large, decentralized wholesaler. These workers take and process orders, and route them to the warehouse for packing and shipment. Often, they must be able to answer customer inquiries about products and monitor inventory levels or record sales for the accounting department. Stock clerks and order fillers code or price goods and store them in the appropriate warehouse sections. They also retrieve from stock the appropriate type and quantity of goods ordered by customers. In some cases, they also may perform tasks similar to those performed by shipping and receiving clerks.

Like office and administrative support workers, sales and related workers typically do not need postsecondary training, but many employers seek applicants with prior sales experience. Generally, workers in marketing and sales occupations try to interest customers and assist them in purchasing a wholesale firm's goods. There are three primary types of sales people in wholesale firms: Inside sales workers, outside sales workers, and sales worker supervisors.

Inside sales workers generally take sales orders from customers. Counter clerks wait on customers who come to the firm to make a purchase. Outside sales workers, also called sales representatives or sales engineers, are the most skilled workers and one of the largest occupations in wholesale trade. They travel to customers' places of business—whether manufacturers, retailers, or institutions—to maintain current customers or to attract new ones. They make presentations to buyers and management or may demonstrate items to production supervisors. Sales representatives must be very knowledgeable about product operation, prices, maintenance needs, and capabilities and must be thoroughly familiar with customers' needs and business goals so that they can suggest how customers can use products to their greatest advantage. For example, sales representatives or sales engineers sometimes advise manufacturers on how to use a new piece of equipment to make production more efficient or may train workers to use the equipment. In the case of complex equipment, sales engineers may need a great deal of highly technical knowledge. For this reason, some outside sales workers need to have postsecondary technical education. Sales representatives and sales engineers also may be known as manufacturers' representatives or agents in some wholesale trade firms. Sales worker supervisors monitor and coordinate the work of the sales staff and often do outside sales work themselves.

Transportation and material-moving workers move goods around the warehouse, pack and load goods for shipment, and transport goods to buyers. Laborers and freight, stock, and material movers manually move goods to or from storage and help to load delivery trucks. Hand packers and packagers also prepare items for shipment. Industrial truck and tractor operators use forklifts and tractors with trailers to transport goods within the warehouse, to outdoor storage facilities, or to trucks for loading. Truck drivers transport goods between the wholesaler and the purchaser or between distant warehouses. Drivers of medium and heavy trucks need a State Commercial Driver's License (CDL). Driver/sales workers deliver goods to customers, unload goods, set up retail displays, and take orders for future deliveries. They are responsible for maintaining customer confidence and keeping clients well-stocked. Sometimes these workers visit prospective clients, in hopes of generating new business.

Management and business and financial operations workers direct the operations of firms. General and operations managers and chief executives supervise workers and ensure that operations meet standards and goals set by top management. Managers with ownership interest in smaller firms often also have some sales responsibilities. First-line supervisors oversee warehouse workers—such as clerks, material movers, and truck drivers—and see that standards of efficiency are maintained.

In order to provide manufactured goods to businesses, governments, or institutional customers, merchant wholesalers employ large numbers of wholesale buyers and purchasing managers. Wholesale buyers purchase goods from manufacturers for resale, based on price and what they think customers want. Purchasing managers coordinate the activities of buyers and determine when to purchase what types and quantities of goods.

Many wholesalers do not just sell goods to other businesses; they may also install and service these goods. Installation, maintenance, and repair workers set up, service, and repair these goods. Others maintain vehicles and other equipment. For these jobs, firms usually hire workers with maintenance and repair experience or mechanically inclined individuals who can be trained on the job.