[inquisitor]

LTE is inaccessible for T-Mobile's prepaid subscribers. Prepaid LTE is only available to eplus customers (including all of their MVNOs) and Vodafone CallYa customers who do subscribe to an LTE tariff option. As eplus' LTE coverage is quite limited, Vodafone is the only choice here.

By the way O2 and eplus have already opened up large parts of their 3G networks for biliteral national roaming which has significantly improved 3G coverage for customers of both former operators who have recently merged. The national roaming will be limited to 3G, so no chance for eplus subscribers to make use of O2's better LTE coverage. However O2 expects to have fully integrated both LTE networks by middle of 2016 by which time LTE may be activated for all kind of customers.