A split order in retail occurs whenever an order is fulfilled in more than one shipment. This entails additional costs to the retailer. In the context of electronic commerce retail, we study the problem of assigning stock-keeping units to distribution centers (DCs) to minimize split orders to satisfy customers and companies. We show that this problem is NP-hard, propose several heuristics and test them against other benchmark algorithms. We evaluate the results of the test along three dimensions: the average number of shipments per order, workload balance across the DCs, and the number of DCs that are capable of fulfilling a particular order.