10 Pesos

Negros Occidental's guerrilla currency was authorized under the Commonwealth government-in-exile framework after Japanese forces occupied Manila in January 1942. Provincial and local authorities across the Philippine islands scrambled to produce their own emergency notes to keep local economies functioning — the Negros issues are among the better-documented of these provincial series, backed nominally by provincial funds rather than any central reserve.

The S639 designation places this firmly within the Philippine guerrilla note classification. Counterfeiting of provincial issues was a known problem during the occupation, and some Negros notes circulated alongside Japanese Military Pesos, creating genuine confusion about relative value.