It is planned that 900MHz (Band 8.) and 800MHz (Band 20) will be supported by the Deutsche Telekom NatCos in Europe:

Austria - B8 (900 MHz) Croatia - B20 (800 MHz) Czech Republic - B20 (800MHz), eventually B8 (900 MHz) Germany - B8 (900 MHz) Greece - B20 (800MHz) Hungary - B20 (800 MHz), eventually B8 (900 MHz) Poland - B20 (800MHz) Slovakia - B20 (800MHz), eventually B8 (900 MHz) The Netherlands - B8 (900 MHz) USA - B12 (700 MHz), also B2 (1900 MHz), B4 (1700 MHz)

Our existing LTE infrastructure allows an efficient integration of NB-IoT. For the most part NB-IoT will be deployed to our LTE radio access network via software upgrade. As NB-IoT can be deployed both in the GSM or the LTE spectrum, no additional spectrum licenses are needed.
This technology supports different spectral operation modes, making its deployment flexible and adaptable to different regional network implementations, e.g. stand-alone, guard band or in-band operation. Additionally, components specified by the 3GPP for NB-IoT were set up, e.g. core network elements.
In Europe target Bands 20 (800 Mhz) & Band 8 (900Mhz). More information can be found here.