10 Ringgit

Brunei adopted polymer for this denomination as part of a broader regional shift — Malaysia, Singapore, and several Pacific issuers were all moving to Guardian substrate through the 1990s, and Note Printing Australia was the dominant supplier pushing the technology. What makes the Brunei polymer series worth noting is the interchangeability agreement underpinning the entire currency system: Brunei ringgit and Singapore dollars have been exchangeable at par since 1967 under a formal Currency Interchangeability Agreement, meaning these notes circulated effectively across both jurisdictions at face value.

The clear window is integral to the Guardian substrate itself, not an added feature — a distinction that matters when assessing security architecture.