Is it Lawful to Give Charity on their Behalf
Question:
A number of years ago, I took a sum of one hundred Saudi Riyals from a number of my colleagues, after which, I travelled to another area and forgot those colleagues and they also forgot me. Now I do not know where they are, so what should I do with the sum of money which is my responsibility? Inform me and may Allah reward you with goodness.
Answer:
If the matter is as you have mentioned in your question, which is that you forgot the owners of the hundred (Riyals) then it is lawful for you to give charity on their behalf. Then if you remembered any of them you must give him his right, unless he approves of your having given it in charity on his behalf. In that case, you will be absolved from blame and you and them will be rewarded.
Source :
Shaykh `Abdul-`Azeez Bin Baz
Fatawa Islamiyah, volume 5 / page 27