Tmobile is technically different companies in Europe and US, although Tmobile in Europe owns 43% of Tmobile US, and interestingly, the German government owns 32% of Tmobile Europe.
Tmobile is also widely considered to be the worst of the 3 US mobile networks (Verizon is considered to have the best coverage, then ATT, then Tmobile). Their pricing reflects that too, as Verizon is the most expensive, then ATT, then Tmobile.
https://en.wikipedia.org/wiki/T-Mobile_US
https://en.wikipedia.org/wiki/Deutsche_Telekom
Tmobile is also widely considered to be the worst of the 3 US mobile networks (Verizon is considered to have the best coverage, then ATT, then Tmobile). Their pricing reflects that too, as Verizon is the most expensive, then ATT, then Tmobile.