5 000 000 000 Mark

Reutlingen was among hundreds of German municipalities that issued their own emergency currency — Notgeld — as the Reichsbank's hyperinflationary spiral made official denominations obsolete almost as soon as they were printed. By late 1923, when this note was issued, five billion marks was a transactional sum, not a statement of value. The Reichsmark reform of November 1923, at a conversion rate of one new mark to one trillion old ones, rendered the entire series worthless within weeks of printing.

The watermark is atypical for municipal emergency issues of this period; most Reutlingen Notgeld at lower denominations was printed on plain stock, making the security paper here an unexplained upgrade — possibly borrowed from a commercial printer's existing supply rather than a deliberate anti-counterfeiting measure.