20 Mark
€219,027.00
| Issuer | Altona, City of |
| Year | 1918 |
| Type | Local banknote |
| Value | 20 Mark |
| Currency | Mark (1914-1924) |
| Composition | Paper |
| Size | 140 × 90 mm |
| Shape | Rectangular |
| Printer | H. W. Köbner & Co. GmbH, Altona, Germany |
| No. printed | |
| Designer(s) | |
| Engraver(s) | |
| In circulation to | |
| Reference(s) | DeNG 3#012.08 |