This book examines the role of interpersonal trust in underpinning trade in the eighteenth-century Atlantic world. It focuses on the nature of mercantile activity in two parts of Spain: Cadiz in the south and its trade with Spain's American empire; and Bilbao in the north and its trade with western and northern Europe. Drawing on a broad range of Spanish Peruvian and British sources the book explores processes of trade trading networks and communications.