In 1909, the legal tender status for currency issued by the Reichsbank in Germany was modified through the Gesetz über den baren Zahlungsverkehr (Law on Cash Payments) enacted on June 1st. Prior to this law, the Reichsbank notes were not considered legal tender, meaning they did not have to be accepted as a form of payment across the German Empire. The law of 1909 changed this, making Reichsbank notes legal tender throughout Germany. This amendment allowed for greater uniformity in transactions and increased the stability and influence of the Reichsbank's currency within the empire.

This change was part of a broader effort to stabilize and standardize the currency system in Germany, further centralizing financial control and simplifying commerce.

For more detailed historical context, you might want to consult sources like archives of German economic history or specialized publications on the monetary systems of early 20th century Europe.