The lack of currency, which affected the whole economy of New Spain, was an extremely serious problem in the northern provinces of the viceroyalty. In this paper, the author explains how that problem had a palliative since 1773, when the traders that negotiated in Sonora and Chihuahua started to utilize drafts (libranzas) of the Royal Treasury (Real Hacienda) to transfer monetary values to their creditors in Mexico City. Notwithstanding the advantages obtained by the traders and by the local offices of the Royal Treasury, the practice was repeatedly objected by the officers in charge (oficiales reales) of the royal cash (real caja) located in Mexico City.El problema de la escasez de moneda, que se resintió de manera general en la Nueva Espa...