Great news! Every Tonie works with every Toniebox, so you can have a US Toniebox and play EU Tonies, and vice versa.
The only difference between the Tonieboxes is the included charging station. The US version of the Toniebox charging station is only compatible with 120V outlets while the EU version of the Toniebox charging station is compatible with 120-240V outlets.
As a result, if you would like to use the US charging station in a region that utilizes 220-240V outlets, you would need to use a converter, which would change both the voltage and also allow the plug to fit the outlet. The US charging station will work normally as long as you are using a voltage converter to bring the voltage down to 120V.
If you have any additional questions, send us a message and we will be happy to help!