4 Shillings

The Tongan pa'anga system was not yet in place when this note circulated — Tonga retained British-style pounds, shillings, and pence until decimalisation in 1967, which makes a 4 Shilling denomination a direct reflection of local commercial custom rather than any standard British template. The denomination has no parallel in sterling practice; it emerged from Tonga's own pricing habits.

De La Rue printed this series across a thirty-year window without significant design revision, an unusually long plate life even by colonial issuing standards.