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 is His slave and Messenger. We ask Allaah to exalt his mention as well as that of his family and all his companions.
We do not know that any scholar who said that it is an obligation on the son to seek his father's permission in handling his own money, either gifting it, or giving it in charity, or buying or selling and the like, if the son is mature and has a sound reasoning. On the other hand, if he seeks his father's permission out of respect to him and being polite, then that is better.
Allaah Knows best.