Warehouse invoices rarely fail because of one dramatic overcharge. They fail because storage days, pick fees, and carton minimums are counted on different calendars than your operations team uses.
Start with the rate card, not the invoice total. Confirm whether storage is billed by pallet, cubic metre, or location day, and whether the day count includes the inbound and outbound dates. Many Taiwan third-party warehouses bill both; your own dock log may only count one.
Next, isolate handling codes. Cross-dock, relabel, and rush-pick lines often reuse the same description as ordinary picks. Match each code to a shipment reference before you accept the quantity.
Finally, check minimum charges against actual volume for the month. If your inventory dipped mid-month, a floor minimum can quietly exceed the unit rate you negotiated. Flag those months for a credit discussion rather than absorbing them as normal cost of goods.
When DistSysNet reviews a warehouse account, we build a simple grid: rate card rule, invoice line, shipment evidence, and exception status. That grid becomes the recovery worksheet your AP team can send without rewriting the history of every pallet move.