Using multiple suppliers can bring many benefits to your dropshipping business, such as increased product availability, faster delivery times, and reduced reliance on a single source for your products. However, when you have multiple options for filling an order, how do you know which supplier to choose? Here are a few methods to consider:

1. Consider the location of the supplier and the customer. If the supplier is located closer to the customer, it may be more efficient to use them for the order.
2. Look at the cost of the products from each supplier. It may be more cost-effective to choose the supplier with the lower prices, as long as their product quality is up to par.
3. Check the delivery times offered by each supplier. If one supplier can get the product to the customer faster, it may be worth using them, even if it's at a higher cost.

By considering these factors, you can make informed decisions about which supplier to use for each order and help ensure a smooth and efficient fulfillment process.