Is giving charity on behalf of the deceased upon hearing the news of their death, with the intention of benefiting them after their deeds have ceased, considered an innovated act (bid'ah) or a good custom?

The reward for charity reaches the deceased by consensus, and this is supported by the hadith of Aisha (may Allah be pleased with her) in which a man asked the Prophet (peace be upon him) about the reward for his mother if he were to give charity on her behalf, and he replied, "Yes." It is also supported by the hadith of Ibn Abbas (may Allah be pleased with them both) in which Sa'd ibn Ubadah asked the Prophet (peace be upon him) about the benefit of charity for his deceased mother, and he replied, "Yes."

Al-Nawawi, Ibn Qudamah, and Ibn Taymiyyah affirmed that charity, supplication (du'a), and repaying debts reach the deceased. There is no distinction in this regard between a close relative and a distant one, and the Prophet (peace be upon him) demonstrated this by repaying the debt of the deceased.

Sheikh Ibn Uthaymeen said: The hadith about the cessation of a deceased person's deeds except for three things does not prevent charity given by others from reaching him, as indicated in Aisha's hadith.

Therefore, what this person is doing is not an innovation; rather, it is a virtuous act for which he will be rewarded.