Is it permissible for a travel agent to take the luxurious travel expenses allotted to him by the company, then use ordinary transportation and save the money, while ensuring timely arrival and safeguarding the company's trust? And is he sinful for what he previously took out of ignorance?

The reference for determining the permissibility of benefiting from the difference in travel expenses lies in the company's terms and regulations. If the company grants the employee expenses regardless of the actual costs, then there is no harm. However, if the expenses are only in exchange for actual costs, then it is not permissible to benefit from the difference, and it must be returned to the company without the need to inform them. Rather, the money should be returned by any means that does not cause harm or embarrassment.