This article examines the fiscal transformation of Spain's trade with Spanish America during the 17th century. It analyses the taxation of trade combined with the evolution of the Hispanic Monarchy's long-term domestic debt. To this end, the author looks at the almojarifazgo de Indias (main customs duty), its juro (annuity) obligations and the evolution of the transatlantic trade. He argues that the fall in customs revenue and the increasing non-payment of the juros issued against the almojarifazgo were neither a consequence of the alleged crisis of the Carrera de Indias nor of the higher incidence of fraud. The Crown was not interested in exerting greater fiscal pressure on the trade or fighting fraud at the customs houses of Seville and Cadiz as the increased tax revenue would have gone entirely to service the unpaid juros. Instead, the fiscal burden shifted towards extraordinary contributions that were free of juro obligations.

New estimates of Spain's current-account balance with the «Indies» add new perspectives to the recent debate on the aims and results of Spanish commercial policy. At the height of «comercio libre» in 1784–92, Spain's private commercial interests appear to have drawn larger financial returns from the Indies than did their British counterparts from wider colonial engagement. On this as on other scores, by the eve of the French wars the Spanish empire appears to have become a sounder economic proposition than might be inferred from recent pessimistic views. The empire's subsequent demise may have involved a greater degree of geographical and dynastic accident than is seemingly apparent.

This article analyses various transformations that took place within the Spanish colonial trade before the implementation of the 1778 free trade regulations. Firstly it shows the changes in the pattern of trade caused by the adoption in 1739 of the system of register ships (single «registered» ships), which resulted in the cancellation of the traditional system of fleets. Secondly it examines the role of transatlantic mail in shaping a new, increasingly retail-oriented pattern of trade. Finally, it deals with the evolution of the flow of commercial information crossing the Atlantic, stressing the growing impact of fashion. The primary sources used are mainly letters belonging to Spanish merchants that were confiscated by the British during the eighteenth-century wars.