Is
it permissible for a person to give up his telephone number in return for
the person to whom he gives it up paying his bill,
the amount of which is already known?
I put this question to my shaykh, Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allaah have mercy on him), who replied as follows:
I do not see any reason why not. Giving up something is more general than selling. And Allaah knows best.