Teams handset remove access to org contacts

Hello,

Currently we are rolling out new team handsets Polycom ccx400 and I need some of theses to be a public phone but currently they still give access to the internal contacts when calling giving people access to search all members within the company and giving access to email address and numbers.

Is there a way to remove access to the so that no internal members can be searched for or contacted via the handset with teams installed?

On the handset I create a user account e.g publicphone@******.com and assign a ms domestic calling plan, ms audio conference and comman area phone.

Thanks 

James