What is the ruling on selling mobile phones by installment, and what is the ruling on selling electrical appliances (refrigerators and air conditioners) by installment, knowing that I transferred the value of the air conditioner to the customer so that he could purchase it himself?

Purchasing a mobile phone, taking possession of it, and then selling it to someone who has promised to buy it in installments is permissible. However, selling a refrigerator before taking possession and acquiring it, and selling an air conditioner by authorizing the buyer to purchase and take possession of it—the majority of scholars prohibit this. The more cautious approach is to sell the item in installments after owning and transporting it.