Is it permissible to work as an accountant and contracts writer in a showroom that sells electrical appliances on installment, where goods are bought from the showroom’s account at a certain price (e.g., 1075), then the buyer sells them on credit to a customer at a higher price (e.g., 1800) in installments, and then the showroom buys the goods from the customer in cash at a lower price (e.g., 1000)?

This transaction is a prohibited usurious trick called a "triple or triangular trick," because it involves three parties.

Ibn Taymiyyah and Ibn Uthaymeen, may Allah have mercy on them, clarified some forms of it and explained that resorting to tricks to legitimize something forbidden only increases its wickedness.

This transaction is based on two violations: 1. Selling the commodity in its place without taking possession of it. 2. Reselling the commodity to the showroom with prior collusion, so it appears as a sale while its reality is a usurious loan.

Accordingly, it is not permissible to work in this prohibited field, and the showroom owner must be advised by clarifying the prohibition of this transaction. It is permissible to work in another permissible field if possible.