I am a treasurer in a company. Is it permissible for me to benefit from the money in my trust along with protecting it without my employer's permission?

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.

It is impermissible for you to use the money which you are entrusted to protect by the employer unless he allows you to do so. A trustee is not allowed to dispose of the trust except according to the owner’s conditions. If such a trustee violates these conditions, he is deemed guilty. Anas narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “Muslims must fulfill the stipulated conditions as long as they conform to the right way.” [Al-Haakim; Al-Albaani: Saheeh]

Allaah Knows best.