Outsourced fulfillment is priced as a set of separate charges rather than a single rate. Understanding which ones scale with what explains why quoted costs and actual invoices diverge.
Charges attach to each stage of handling
Goods are billed on receipt, usually by pallet, carton or unit, with additional charges when shipments arrive unlabeled or improperly packaged.
Storage is billed for space occupied over time, typically per cubic foot or per pallet position per month, which makes bulky low-value products expensive to hold.
Outbound charges cover picking each item, packing the order and the shipping label itself. Multi-item orders cost more to assemble than the shipping difference suggests.
Volume and velocity drive the total, not units
Two products with the same price behave very differently if one is dense and one is bulky. Storage cost tracks the space, not the value.
Duration compounds this. A product that turns quickly occupies space briefly, while a slow seller accrues storage indefinitely against a fixed margin.
Long-term storage surcharges exist precisely to price this. Goods held beyond a defined period are billed at higher rates to discourage using the warehouse as dead storage.
Exception fees are where budgets break
Relabeling, repackaging, bundling, oversized handling, removal orders and disposal all carry separate charges triggered by conditions the seller may not anticipate.
Returns processing is its own line: receiving, inspecting, restocking or disposing, each priced individually and each incurred on an item generating no revenue.
These charges are individually small and collectively significant, which is why cost per order calculated from the headline rates understates the real figure.
Peak periods reprice everything
Providers raise storage and handling rates during high season because space and labor are constrained. Inventory positioned early for peak is charged at those rates.
Capacity limits also appear, restricting how much a seller may send in. Planning that assumes unlimited inbound capacity fails at exactly the wrong time.
The result is a tension between holding enough stock to meet peak demand and avoiding the cost of holding it through the expensive months.
Contract terms decide the exit
Minimum monthly commitments, notice periods and removal charges determine how easily a seller can leave. Retrieving inventory is billed per unit and takes time.
Splitting inventory across providers or regions reduces dependency and shipping distance, at the cost of holding more total stock and more complex allocation.
Because fee schedules are revised periodically and vary by provider, the comparison worth making is total cost per order across a full year of actual mix, not the rate card.