It only works (and works well!) only when it is outside of the case I have put the phone in. I have a very thin protective case (Terrapin Slim Fit Xperia Z5 cover I bought at the same time) but, whichever adjustment shim I use, there is not enough length in the plug to charge the phone. It really needs some adjustment for the plug length. It maddening to have to keep taking the phone out of its cover.