5 000 000 000 Mark Overprint on 500 000 Mark

Stendal's billion-mark overprint is a product of Germany's hyperinflation peak in late 1923, when municipal authorities were legally permitted — and practically forced — to issue their own emergency currency, known as Notgeld, to keep local commerce functioning. The Reichsbank simply could not print fast enough. The 500,000 Mark base note was already obsolete almost the moment it was produced; stamping a 5,000,000,000 figure over it was cheaper and faster than commissioning an entirely new design.

The overprint practice also creates authentication headaches. Forged overprints on genuine base notes are documented across the Notgeld series, and the watermark in the paper is the primary check against this.