Caixa were copper coins produced by the Portuguese at Macao using copper they imported from trade interactions with the Japanese. The coins bore a distinctive square hole.

In the 1640s until 1688, these caixa coins, imported into Vietnam by Dutch and Japanese merchants, were the most favored means of exchange in the northern Vietnamese countryside. Gold and silver remained the chief mode of exchange in Pho Hien and other port cities, however.

References

  • Geoffrey Gunn, History Without Borders: The Making of an Asian World Region, 1000-1800, Hong Kong University Press (2011), 230.