What is the ruling on establishing a website for booking hotels around the world via credit card payment, knowing that the hotel database will be retrieved from a foreign website and there is no possibility of reviewing the extent to which these hotels comply with ethical or Sharia controls? And what are the Sharia controls that must be observed in such a project?

Conclusion:

This project is encompassed by aspects of piety (wara‘) and permissibility (jawāz). Piety dictates avoiding such work due to the availability of purely permissible alternatives. Permissibility, however, arises from your mediation for the customer to obtain a permissible benefit (staying in the hotel). However, it is not permissible to assist someone who requests what is unlawful for them. Remember the sayings of the Messenger of Allah, peace and blessings be upon him: "Righteousness is that with which the soul feels tranquility, and sin is that which wavers in the breast," and "Leave what makes you doubt for what does not make you doubt."