What is the ruling regarding the Murabaha seller registering the guarantee in the name of the purchasing client, or handing the device over to him, and what sin does the purchasing client incur, and must he dispose of the device if this occurs?

It is permissible to purchase appliances through Murabaha if the Shariah conditions are met. These conditions are that the Murabih (seller in Murabaha) purchases the commodity for himself and takes possession of it, then sells it. Furthermore, the contract must be free from prohibited conditions. Warranty also transfers with the commodity. There is no objection if the invoice or warranty is issued in the name of the buyer instead of the Murabih, as this is a documentation procedure, and the original intent is that the purchase is made for the benefit of the Murabih.