What is the ruling on dropshipping, which is selling goods from international stores through a personal online store, with the addition of a profit margin, where payment is made to the original merchant after the customer's order, and the original merchant ships the product directly to the customer?

If you conclude a contract with a customer before acquiring the merchandise, this is impermissible because it constitutes selling what you do not own and profiting from what you do not guarantee. To rectify this, the transaction can be a non-binding promise to purchase, where the price is agreed upon, then you acquire the merchandise and sell it to the customer. Alternatively, you can enter into an agency contract with the merchant for a known fee, making you their agent, and then you add your commission to the price. Or, you can sell a commodity described by its characteristics ( bay‘ al-salam ), where the customer pays the price upon concluding the contract, then you purchase the commodity from the merchant and request them to send it to the customer. In this last case, you can stipulate a return option with the merchant for the merchandise if the customer returns it; as for agency, there is no issue with returns.