The Aceh Qanun No. 11 of 2018 pertaining to Islamic Financial Institutions provides legislation and regulations governing the activities of financial institutions in the context of achieving a just and thriving Acehnese economy under the auspices of Islamic law. As a result of this conversion, there are barriers, particularly in the process of transferring finance or credit from conventional banks to Islamic banks, primarily the subrogation process for transferring mortgage rights. This research was conducted using the normative legal research technique. This paper aims to describe the role of a notary in the subrogation of mortgages resulting from the conversion of conventional banks to Islamic banks. When converting credit utilization from conventional to sharia banking, a subrogation method is utilised to transfer customer credit from conventional banking to sharia banking. The subrogation transition practiced by Islamic banking is antithetical to the principle of credit transfer outlined in DSN Fatwa 31/DSN-MUI/VI/2002 on the Transfer of Debt. In essence, notaries have both moral and legal responsibilities. Moral duty entails, among other things, the Notary's commitment to performing his duties and obligations as effectively as possible so that the deed's intended purpose is realized and the deed is valid. Legal obligations include both civil and criminal law responsibilities. Civil law responsibilities pertain to the possibility of a notary being sued for the deed of takeover agreement that the notary drafted. Claims from clients can take the form of lawsuits for default or lawsuits for unlawful acts (onrechtmatigedaad). Regarding making the takeover deed with guaranteed land rights (mortgages), the notary is also responsible, especially in proving the deed, if there is an oversight or mistake that causes the deed to lose its authenticity due to an oversight or mistake.