Is it considered permissible (halal) or forbidden (haram) to increase an invoice for a project valued at one hundred million by twenty million, and then return this amount to the officials after receiving payment, knowing that the project was created for the owner of the study office and has no competitors?

It is not permissible for administrators to take money unjustly, as this constitutes a breach of trust, based on the words of Allah Almighty: "O you who have believed, do not betray Allah and the Messenger or betray your trusts while you know [the consequence]." And the words of the Prophet, peace and blessings be upon him: "Indeed, there are men who delve into the wealth of Allah without right; for them is the Fire on the Day of Resurrection."

It is also not permissible to assist them in this, for the Prophet, peace and blessings be upon him, cursed the one who consumes usury, the one who feeds it, its scribe, and its two witnesses; and the briber, the bribed, and the mediator between them. Assisting in acts of disobedience to Allah makes the helper sinful and burdened with wrongdoing.