500 000 000 Mark

Neumünster's half-billion Mark note dates from the most violent phase of the German hyperinflation — autumn 1923, when municipal authorities across Prussia were issuing Notgeld not as novelty souvenirs but as functional emergency currency, because Reichsbank notes were arriving too slowly and depreciating too fast to cover payroll. Cities, counties, and private firms all printed their own, and the Prussian provincial administration largely looked the other way.

The official stamp is the critical authentication element here. Without it, these notes were explicitly declared invalid by the issuing city — a common condition attached to Neumünster municipal issues of this series.