It is not permissible to sell movable items until after one has taken possession of them
Question

                There is a company which buys furniture and building materials for those that want them. The customer goes to the company and specifies the furniture or building materials that he wants. The customer pays the first instalment, like instalments for cars, and the remainder of the money is paid in monthly instalments, with a rate of as much as 10% for the company. The company gives the customer the receipt so that he can go to the furniture company and get the furniture himself, then the instalments are paid to the company who made arrangements for these instalments. What is the ruling?.
Praise be to Allah.
    The company does not have the right to sell furniture or 
    other movable items until after the transaction has been completed and the 
    sold item has been moved to their property and has been transferred from the 
    possession of the seller to another place, then the transaction is completed 
    after that. 

    As for paying a deposit to the company before that, it is not permissible and they do not have the right to sell anything until after they have taken possession of it and moved it from the seller's place to another place. And Allaah is the source of strength. End quote.