The study discussed the combination of contracts in the practical reality of Islamic financial institutions through the lease contract ending with ownership, in terms of the concept, forms and impact of this contract, as well as clarified the rule of fraud in complex financial contracts in terms of legitimacy and legality, and showed the types of tricks commendable and blameworthy, and explained the relationship of fabrication, fraud and pretexts between them and complex financial contracts, and the study also discussed the legal and legal view of leasing ending with ownership and its treatment . The study relied on the local and federal laws of the United Arab Emirates, such as the UAE Civil Transactions Law No. 5 of 1985, and the UAE Federal Law No. 8 of 2018 on financial leasing, and compared them with laws in Egypt, such as the Egyptian Civil Law No. 131 of 1948, and the Law Regulating Financial Leasing and Egyptian Factoring Activities No. 76 of 2018, while linking them to the reality of Islamic financial institutions in the UAE