Why is No Caller Id showing from a landline despite the number being in my contact list.

As I am sure the majority of phone users do, I have my Home landline stored in my Contacts. Despite this, when my Home landline rings my iphone 5s it shows up as No Caller ID as an incoming call. Yet when I ring my home landline from my iphone 5s it shows an outgoing call to Home. My phone software is iOS 8.1.3. I have tried changing my local STD code to the International Code but this has no effect but in any case I have Dial Assist set to automatically detect the correct international code so I was not surprised this did not work. Anyone have a solution to this please?