What is the legitimate ruling regarding money received as incentives and bonuses by employees from inspection fees imposed on goods coming from outside the country and from other revenues?

The basic ruling on working in customs and tax departments is prohibition, due to their involvement in taking people's money unjustly. However, it may be permissible. The ruling on incentives and bonuses disbursed by the customs department to its employees depends on the status of the customs operation itself: if it is permissible, then the incentives are permissible; if it is forbidden, then the incentives are forbidden, because they involve consuming people's money unjustly. Allah has forbidden this, saying: "And do not consume one another's property unjustly," and the Prophet, peace be upon him, said: "The property of a Muslim is not lawful except with his willing consent."