500 Pesos

The Negros Emergency Currency Board was one of several provisional Philippine authorities that issued guerrilla currency during the Japanese occupation — notes produced clandestinely to keep local economies functioning outside the military administration's control. The occupation forces treated possession of such currency as a serious offense, which meant these notes circulated under genuine risk to their holders.

S667 is among the higher denominations in the Negros series, and high-denomination guerrilla notes were disproportionately likely to be destroyed or hidden as the war drew to a close — either deliberately burned to avoid Japanese discovery or lost when their issuers were compromised.