Is It Halal to Create a Website for Generating Medical Leave Certificates?

If the website merely enables users to prepare, print, or save a medical certificate in a standardized format after it has been legitimately issued by a registered doctor following a genuine medical examination, and it does not allow any false information, forged doctor's signatures, fake stamps, or fabricated medical conditions to be entered, then providing such a technical service may, in itself, be permissible. This is because the certificate is based on truthful information and a genuine medical assessment.

However, if the purpose of the website—or its predominant use—is to enable people to create fake medical certificates without undergoing a doctor's examination, so that they can deceive their employer, company, institution, or any other party in order to obtain medical leave or any financial or other benefit, then creating, operating, or earning income from such a website is not permissible according to Islamic law. This is because it constitutes assistance in sin, deception, and unlawful conduct.

Allah, the Exalted, says:

 ﴿وَلَا تَعَاوَنُوا عَلَى الْإِثْمِ وَالْعُدْوَانِ﴾

"Do not cooperate in sin and transgression." (Surah al-Ma'idah 5:2)

The Messenger of Allah ﷺ also said:

 مَنْ غَشَّ فَلَيْسَ مِنَّا

"Whoever deceives others is not one of us." (Sahih Muslim, Hadith no. 101)

The Hanafi jurists have also explicitly stated that it is not permissible to accept payment for work whose predominant purpose is to assist in unlawful acts, because "الوسائل لها أحكام المقاصد" (the legal ruling of the means follows the ruling of the ends), and assisting in sin is prohibited. (See: Radd al-Muḥtār and Al-Fatāwā al-Hindiyyah, Kitāb al-Ijārah.)