Ask ten online stores what it costs them to ship an order and nine will answer with the carrier's rate. That figure is usually less than half the real cost — and the difference is exactly where the margin evaporates.
The seven components
1. Receiving and storage
Inventory occupies space before it sells. Prorate the monthly storage cost across the orders you actually shipped that month. If your inventory turns slowly, this number hurts.
This is where the billing model matters: leasing fixed area charges the same in January as in November, while renting by occupied pallet position follows your real occupancy.
2. Picking
An operator's time walking the warehouse, locating the product and verifying it. It depends on two things: how many lines the order has and how well organized the warehouse is.
A one-line order and a seven-line order do not cost the same, even though the carrier charges the same.
3. Packing
Box, void fill, tape, label — and the time to assemble it. The most underestimated line, because each component is cheap; the problem is that it multiplies by every order.
4. Freight
The visible line. Varies by weight, volume, zone and carrier.
5. Platform commission
If you sell through a marketplace, the commission is part of the cost of serving that order. If you sell through your own store, the payment gateway fee is.
6. Returns
The line most people ignore, and the most destructive. A return adds:
- Return freight
- Product inspection
- Reconditioning or repacking
- Restocking
- The lost revenue
If your return rate is 10%, every ten delivered orders carry the full cost of one returned. A returned product can cost more than two delivered ones.
7. Shrinkage and errors
Wrong shipments, damaged product, incomplete orders. Each generates a reshipment, a refund, or a customer who does not come back. It is a real cost even when it appears as a line nowhere.
The practical formula
Cost per order =
(monthly storage / orders that month)
+ picking cost
+ packing materials
+ average freight
+ platform commission
+ (total return cost / orders that month)
+ (error and shrinkage cost / orders that month)
Run it with data from a real month, not your best month. And run it twice: once in peak season and once in low season. The gap between those two numbers is usually the revelation.
Why the number swings so much between seasons
Because storage is fixed and orders are not. In November you ship 4,000 orders and storage dilutes; in February you ship 600 with the same space cost, and the proration spikes.
That is the arithmetic that makes many stores profitable in peak season and quietly unprofitable the rest of the year.
The three levers that actually move the number
Turn storage into a variable cost. If space is billed by real occupancy, by month or fraction, low-season proration stops punishing you.
Reduce errors. Every error has a compound cost: the reshipment, the return and the customer. Scan validation at each step is what prevents it, and it requires a WMS that directs and verifies.
Shorten the distance to dispatch. It does not lower direct cost, but it lowers cycle time — and cycle time determines how much safety stock you need to carry.
Where an operator fits
Fulfillment — picking, verifying, packing and dispatching order by order — combined with flexible pallet-position rental turns the two heaviest cost components into variables that follow real demand.
Our Querétaro park sits next to the Intercontinental Airport, where the major parcel carriers operate.