A man communicates with his irrevocably divorced wife on the phone or by any other means for the purpose of checking on his children or for any other purpose. What is the ruling on this, taking into account that she has a guardian and brothers whom the husband can speak with. May Allaah Reward you.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

A woman who was divorced three times becomes a non-Mahram to her ex-husband. So, he is not allowed to contact her through the telephone or any other means, since this might stimulate their desire in a way that could open the door to illegal acts. In case he wishes to ask about his children, he can call her father or brothers, or even arrange for his children to visit him. If, for some reason, he had to speak to her in person, he may do that if he abides by the relevant Sharee‘ah rules.

Allaah Knows best.