In the checkout flow, the shipping rate is determined by the product weight set in Shopify + the destination country. If a product is 2lbs in Shopify, the customer will pay the 2lb rate.
All packages are re-weighed at our facility for billing purposes. There could be a few possibilities as to why you were charged a different shipping rate than what your customer paid at checkout:
- The product weights configured in Shopify may need to be more accurate: We recommend reviewing the weights for your products in Shopify to ensure they are correct.
- The packaging may be affecting the weight of the shipment: We recommend adding some "padding" to the weights in Shopify if the packaging is adding weight to the shipment at billing.
- DIM Weight: During fulfillment for DDP orders, we calculate the shipping rate using the greater between product weight and Dimensional (DIM) weight. For example, if the product ships in a 12x10x6 inch parcel, the DIM weight is 6 lbs (LxWxH/139). So during fulfillment, you will be charged the 6 lb rate. We can recommend ways to help navigate DIM weight, if needed.