20 000 Dollars

By the time this note entered circulation in early 2008, Zimbabwe's inflation rate had already rendered its face value nearly meaningless within days of issue. Fidelity Printers and Refiners — the Reserve Bank's own printing subsidiary — was running presses around the clock to keep pace with denominations that multiplied month by month, a logistical absurdity with few modern parallels.

The colour-shifting ink was a costly security feature on a note whose purchasing power evaporated faster than any counterfeiter could exploit it. Within the same year, the 20,000-dollar denomination would be dwarfed by notes denominated in the hundreds of billions.