THE RULING REGARDING TALKING ON THE PHONE IN TOILET

It is Makrooh, prohibited and impermissible to talk in the toilet using a phone or any other means than a phone. Talking in the toilet is the cause of the displeasure of Allah Almighty, and the displeasure of Allah Almighty is the cause of destruction in this world and the hereafter. It is Makrooh e Tahreemi to talk in the toilet. This Hadith is therefore mentioned in As Sunan Al Kubra Lil Bayhaqi Volume 1, Page 161, under the chapter of "The Aversion (Immense undesirability) of Speaking In The Toilet":

Translation: It is narrated from Hazrat Ibn e Umar RadiAllahu Anh that a person greeted the Holy Prophet صلى الله عليه وسلمwhile He صلى الله عليه وسلمwas passing urine (i.e.

answering the call of nature), but He صلى الله عليه وسلمdid not respond (i.e. reply) to that person's greeting. And it is in Fataawa Shaami:

Translation: It is in Siraajiyah that it is Makrooh to talk in the Masjid, behind the funeral, in the toilet and at the time of Jimā (sexual intercourse).... And it is Makrooh to do so in the toilet because it invites the Wrath (Displeasure) of Allah. (Fataawa Shaami, Volume 11, Page 814/Zia-ul-Quran Publications, Lahore)

In short: Talking on a phone or talking in general in the toilet is Makrooh e Tahreemi and impermissible, and it is also against decency and modesty, which causes the displeasure of Allah Almighty. Therefore, it is necessary to avoid it