50 000 000 Mark

Speyer's 50-million Mark note dates from August–September 1923, the absolute peak of the Weimar hyperinflation. By the time notes of this denomination were being printed by municipal authorities across Germany, the Reichsbank's own supply chain had collapsed under the volume required — cities, towns, and even private firms were legally authorized to issue emergency currency (Notgeld) simply to allow workers to be paid at all.

Speyer, a Rhenish city then under French occupation following the Versailles settlement, operated under additional administrative constraints that made local issue more complicated than in unoccupied Germany. Whether this particular note circulated meaningfully before being rendered worthless by further inflation within days of issue is the real question with any high-denomination 1923 Notgeld.