Is it permissible to cancel airline ticket bookings provided by the company and be compensated with a sum of money, or to cancel the booking and travel by land to benefit from the price of the tickets?

It is permissible for an employee to benefit from the price of airline tickets given to them by their employer by traveling by land or on other airlines to take the price difference, unless the employer prohibits it. The basic principle is to observe the agreement between the two parties, as Allah Almighty says: (O you who have believed, fulfill [all] contracts), and the Prophet, peace and blessings be upon him, said: (Muslims are bound by their conditions). Sheikh Abdul Karim al-Khudair issued a fatwa (definition) permitting the sale of government-issued tickets when they are no longer needed, provided that overland travel does not result in a delay from work.