What is the ruling on the money remaining from transportation expenses that were not fully spent, and does the ruling differ if the employee determines the fare or the company?

The answer is summarized by considering what the company pays the employee: If the money is allocated solely to cover transportation expenses, and any remaining amount must be returned, then any surplus must be returned. However, if the amount is a fixed sum and no refund of the surplus is required, the employee may benefit from what remains with him. The determining factor is the contractual terms agreed upon between the company and the employee, for Allah Almighty says: "O you who have believed, fulfill [your] contracts," (Quran 5:1) and the Prophet, peace and blessings be upon him, said: "Muslims are bound by their stipulations." It should also be considered whether the action constitutes a trick or deception. In the Hadith: "Consult your heart. Righteousness is that about which the soul feels tranquil and the heart feels tranquil, and sin is that which perturbs the soul and causes uneasiness in the chest, even if people give you a verdict [in its favor] again and again."