10 Dollars

The Solomon Islands adopted a decimal currency in 1977 upon establishing the Central Bank, breaking from the Australian dollar that had served as the effective local currency through the colonial period. Thomas De La Rue had printed Solomon Islands notes from the outset of the independent series, and the P#20 continues that unbroken relationship. The single watermark is the sole mechanical security feature — no security thread, no fluorescent inks — which reflects both the low counterfeiting risk historically associated with the islands' small domestic economy and the cost considerations for a currency with limited international exposure.