5 000 000 000 Mark Reichsbahndirektion

The Reichsbahndirektion Altona was one of several regional German railway directorates authorized to issue emergency currency — Notgeld — during the hyperinflationary spiral of 1923. By the time denominations reached the billions, the Reichsbank's own printing capacity was overwhelmed, and rail directorates, municipalities, and private firms were all issuing paper to keep wages paid and commerce moving. Altona was then still an independent city under Prussian administration, separate from Hamburg, which gives this issuer a distinct jurisdictional identity.

The five-billion-mark figure dates this note to the autumn acceleration phase, when the mark's purchasing power was collapsing by the hour.