How 3PL Billing Works — Storage, Handling & Shipment Charges Explained

Every 3PL invoice, regardless of vendor, is structured around three categories of charges: storage, handling, and shipment. Understanding these three is the foundation for everything else in 3PL billing.

Storage charges compensate you for warehouse space occupied by a customer's inventory. They are typically billed per pallet, per cubic foot, per square foot, or per handling unit — accrued daily or monthly depending on the contract.

Handling charges cover the operational labor of moving inventory through the warehouse. Receiving fees, putaway charges, pick fees, pack fees, and special-service charges (kitting, labeling, photo verification) all fall in this category.

Shipment charges cover the outbound logistics — typically the carrier label cost plus your margin uplift. Some 3PLs roll this into the handling charge; others bill it as a separate line item with transparent carrier cost passthrough.

Storage is the most-misunderstood category. The naïve approach is to count pallets at month-end and multiply by the rate. This fails the moment a customer's inventory volume changes mid-month — which it does, constantly.

The correct approach is daily accrual. For every day a unit of customer inventory sits in your warehouse, a small storage charge accrues. The charge is the daily rate (monthly rate / 30 days, typically). Multiply by the number of units. By month-end, the accrued total is the storage charge — and it accurately reflects the inventory profile over the month, not just on the 30th.

Tiered storage adds a second wrinkle: inventory that sits more than 30 days might get a higher rate. Inventory more than 90 days might be considered slow-moving and billed differently. The accrual engine has to know each unit's age, not just count.

Handling charges are the operationally noisy category. The question is always: what counts as a billable event?

Common billable events: inbound receipt (per carton or per pallet), putaway (per handling unit), pick (per line, per unit, or per order), pack (per order), and special services (per occurrence).

The 3PLs that struggle here are usually missing one of two things: (a) the rate card doesn't enumerate every billable event explicitly, leaving operations to bill ad-hoc, or (b) the WMS doesn't capture the event with enough specificity to bill it. Both lead to under-billing.

Shipment billing is where 3PL margin is won or lost. The structural choice is whether to bill clients on a passthrough basis (carrier cost + fixed markup) or a blended basis (your published rate card, regardless of underlying carrier cost).

Passthrough is transparent and easier to defend in customer disputes. Blended captures more margin but requires careful management of carrier negotiations and rate publication.

Either way, the shipment charge must reconcile against the actual carrier invoice — otherwise you are bleeding margin to carrier billing errors. This is where carrier reconciliation becomes a critical billing workflow.