Why the invoice lies to you

When you look up what a product costs, you look at the purchase price. It is the number on the invoice, it is the number in the system, and it feels like the truth. It is only the beginning of the truth. Between your supplier’s warehouse and your customer’s hands, the same product picks up costs that never appear on that invoice and are rarely traced back to it.

These are the linked costs, and they behave differently from the ones in a normal calculation: they depend less on the product and more on the arrangement. Change who collects and who delivers, and the product has a different cost without anything about the product changing at all.

The same deal, arranged two ways

Take one product with a purchase price of 100 and 5 of your own handling. In arrangement A, the supplier delivers to your warehouse and the customer collects from you. In arrangement B, you collect from the supplier and you deliver to the customer. Nothing else differs.

The two prices are 25 percent apart, and every number about the product itself is identical. That is the whole point. If your calculation stops at the purchase price and your own labour, both arrangements look like a 105.00 product, and you will price them the same.

The costs that usually go missing

Go through a real order and ask, for each item below, whether it is in your price. Most businesses find two or three that are not.

• Getting the goods to you. Freight, fuel surcharges, customs handling, pallet fees. Often invoiced separately, weeks later, by somebody who is not the supplier, which is exactly why it never reaches the product.
• Getting the goods out. The courier, the packaging, the labour of packing. If you offer free delivery, this is not free, it is a discount you have decided to give without writing it down.
• Getting paid. Card and gateway fees, cash on delivery charges, and the cost of money when a customer pays in sixty days rather than eight.
• Getting goods back. The return journey, the inspection, the repackaging, and the share that cannot be sold again at full price. In some categories this is the largest linked cost of all.
• Holding the goods. Everything sitting in the warehouse is money standing still, which is a cost even when nobody invoices it.

What to do with the number once you have it

The useful part is that most linked costs are not fixed by nature. They sit with whoever agreed to carry them, which means they are a subject for negotiation rather than a fact of life.

Once you can see that arrangement B costs 26.00 more per unit, three conversations become concrete. You can ask the supplier to deliver, which moves 10.00 of it. You can price collection and delivery separately instead of burying them, so the customer chooses and pays for the convenience. Or you can keep the arrangement and charge 157.20, knowing exactly what you are charging for. All three are fine. Not knowing which one you are doing is not.

Getting these costs onto the product

The reason linked costs escape is structural. They arrive as separate invoices, in different weeks, from carriers and payment providers rather than from the supplier of the goods. Nothing in that flow connects them back to the article they belong to unless something does it deliberately. A system that lets you add transport and handling to a goods receipt, so that the cost lands on the item rather than in a general expense account, is what turns this from an annual surprise into a number you can read per product. That is also the input for the cost price and selling price calculation, and for knowing your break-even point.