50 000 000 000 Mark

Aachen's municipal and district authorities issued this note jointly — an unusual arrangement reflecting the administrative fusion of Stadt and Landkreis for emergency currency purposes during the hyperinflation peak of late 1923. By the time denominations in the billions and trillions were circulating across Germany, a fifty-billion-mark note was functionally small change; the Reichsbank's own figures show the mark losing roughly half its value every few days in October and November of that year.

The dual signatures — one from the acting Oberbürgermeister, one from the Kreisausschuss chairman — were a legal formality required to validate the joint issuing authority.