Verizon is blocking Microsoft’s new Lumia 950 and Lumia 950 XL from being used on its network, according to sources familiar with the situation. The devices have the hardware required to use Verizon’s bands, but the carrier will not allow them to connect.

The Lumia 950 and Lumia 950 XL are only available through AT&T in the U.S., but both handsets ship unlocked and have radios that are compatible with Verizon’s CDMA network. However, don’t think you can buy one and put a Verizon SIM in it.

Speaking on the Windows Weekly podcast this week, Mary Jo Foley explained that Verizon will not authenticate Microsoft’s new devices on its network, so customers will not be able to use them with Verizon SIMs. You can watch this at around 1:01:00 in the video below.

Verizon reportedly has no interest in offering support for these phones, or indeed the Windows platform on the whole, it is claimed. And unlike most other carriers, Verizon’s CDMA network requires a device’s MEID number to be authorized before it can connect.

If an MEID isn’t listed in Verizon’s database, then — or the MEID number has been blocked — the handset associated with it simply cannot obtain service from Verizon. This kind of process is not necessary for GSM carriers like AT&T and T-Mobile.

To avoid any confusion, and to prevent customers from buying these handsets with the intention of using them on Verizon, Microsoft has reportedly disabled CDMA compatibility altogether, so only GSM support is available as standard.

Foley and Paul Thurrott insist Microsoft should not be blamed for this; it is Verizon’s choice not to support the Lumia 950 and Lumia 950 XL. It’s not the first time the carrier hasn’t been all that supportive of Windows phones, either.