5 Colones

The Banco Mercantil de Costa Rica was a private commercial bank operating under Costa Rica's free banking arrangements of the late nineteenth and early twentieth centuries, when multiple institutions held concurrent note-issuing rights. The American Bank Note Company in New York produced paper for several of these competing Costa Rican issuers during the same period, meaning the physical production quality tells you little about relative scarcity — the issuing bank's own fortunes matter far more here.

Costa Rica's government progressively consolidated note-issuing authority after 1900, and private bank circulation privileges were eventually extinguished. How much of this series survived that transition, rather than being redeemed and destroyed, is the real question for any collector.