5 Colones

Banco Nacional de Costa Rica was established in 1914 as a state-owned institution and held a dominant position in Costa Rican monetary affairs through the 1930s. This note predates the 1950 creation of the Banco Central de Costa Rica, after which the Nacional progressively ceded its note-issuing functions — making the late-1930s series among the last actively circulated issues bearing this authority in a purely central banking role.

The American Bank Note Company's involvement with Central American issuers during this period was extensive enough that plate designs were occasionally shared or adapted across clients. Whether that applies here is worth checking against the broader ABNC Costa Rica archive.