500 000 000 Mark

Frankfurt's municipal administration became a de facto currency issuer during the hyperinflation of 1923, alongside hundreds of other German cities and districts printing notgeld simply to meet payroll. By the time denominations had reached nine zeros, the Reichsbank's supply chains were overwhelmed and local printers like Gebrüder Fey were absorbing the overflow — not as licensed note printers in any traditional sense, but as job printers pressed into monetary service.

The 500,000,000 Mark figure, staggering as it reads, was already obsolescent within weeks of printing. Frankfurt's municipal series from this period is reasonably well documented but individual print runs were rarely recorded with precision.