10 000 000 000 Mark

Flensburg's ten-billion-mark Notgeld was issued in October 1923, deep inside the hyperinflationary collapse that made the Reichsmark functionally worthless within weeks of any printing run. Municipal authorities across Germany were issuing emergency denominations simply because the Reichsbank could not produce currency fast enough to keep pace with price increases that were, by that point, doubling daily.

Aug. Westphalen was a local commercial printer — not a specialist banknote firm — which was entirely typical of Notgeld production by late 1923, when security printing had long since become irrelevant to the task. Flensburg's particular position near the Danish border gave it slightly different economic pressures than inland German cities; Danish krone were circulating informally in the region as a de facto stable alternative.

The Rentenmark introduction on 15 November 1923 rendered notes like this one obsolete almost immediately after issue.