Share contacts between mobile devices

Hello,

I am currently using Exchange. I am trying to sync contacts on Windows Phone/iOS between two accounts (I want to add contact on one phone so other could see it). 
How my situation looks like:
2 Exchange accounts configured with my domain

2 Windows Phone (2x Lumia 735) 

I checked everywhere in OWA and WP settings but I am unable to see what I am doing wrong. Any advices?

Cheers!