20 Francs

The Banque de la République du Burundi's 20-franc note had an unusually long production run for a low denomination — the P#27 series spans three decades under Thomas De La Rue, bridging Burundi's turbulent post-independence decades through the catastrophic civil war of 1993–2005. That a single note design survived that period without redesign says more about institutional inertia than monetary stability.

De La Rue's involvement with Burundi dates to the early post-independence years, and the 20-franc was among the lowest-value issues kept continuously in circulation, meaning surviving examples in any decent state are harder to source than the higher denominations.