100 000 000 000 Mark

Heidelberg's municipal emergency currency issued at 100 billion Mark places this note squarely in the catastrophic final weeks of German hyperinflation, when the Reichsbank could not physically print denominations fast enough and local authorities were legally authorized to issue Notgeld to cover payrolls and daily transactions. By November 1923, a single US dollar was worth roughly 4.2 trillion Mark — meaning this note represented a fraction of a cent in real purchasing power at issue.

The dry seal authentication was added precisely because municipalities had minimal anti-counterfeiting infrastructure; forging local Notgeld had become a cottage industry by mid-1923.