My 928 blocks calls when I put my T-Mobile SIM in, but doesn't work with Verizon. Its specific to Verizon's network, not necessarily the phoneOn Nokia Lumia 822, but it works completely,I'm not on Verizon, I'm on Wal-Mart's Family mobile(T-Mobile), and I'm pretty sure after they fix problem we will be the ones who can't block calls because they give non Verizon users problems.