UPS Shipping - Multiple Cartons

We are having an issue with the UPS not quoting the correct pricing when we have to ship more than one carton for an order. On some of our orders, we need to ship multiple boxes, the shipping quotes only as if the weight was for one single box which is considerably lower and causing us to lose money. How can we get an accurate shipping rate if the order is for multiple boxes?

For example: to ship one box of 13 pounds to California, I got a quote of $22, our actual cost on our UPS account would only be $18. To ship two boxes with a total weight of 13 pounds the quote through the Eshop ups plugin came out the same. However our actual cost because of it being two packages rose to $27. In this example the customer was quoted a shipping cost of $22, and it would have cost us $27 to ship the items. How can we set up Eshop/UPS to show multiple packages so that it can be quoted correctly?

You can't. Eshop sends the weight to UPS via the API. There is no way for Eshop to recognize how many boxes a shipment will take.

UPS API then uses that weight, ship to address, ship from address and the generic "package size" in the plugin to determine the shipping cost and returns that value from the API to the cart.

To get around this, in our shipping policy and terms and conditions, we state that UPS is not exact and there will be either an overcharge or an undercharge on many occasions. In those instances, we contact the customer and either give them the overcharge back or charge them the balance if we under charged them.

I will say that there is an option which allows you to do as you want. Its called UPS Ship Manager software, and you get it from the UPS website and your account Rep over at UPS. It allows you to build out the whole shipment in a desktop app. So you know exactly how much shipping will be. Then just call the customer for the shipping and dont even worry about charging the shipping in the cart. a simple "Shipping" terms page explaining that shipping will be calculated and the customer will be called with the final shipping quote should suffice.