Who decides what
was delivered.
Not the seller, and not the buyer. A third party measures, samples and certifies — and under most contracts it is their figure the invoice follows.
Every physical cargo raises two questions that both sides have an interest in answering in their own favour: how much was there, and was it what it was supposed to be. Independent inspection exists so that neither side answers them.
An inspection company is appointed — the internationally recognised names include SGS, Intertek, Bureau Veritas and Saybolt, and most contracts name either a specific one or a mutually acceptable equivalent. They attend at the load port, and normally again at discharge, and they work to published methods rather than to instructions from whoever is paying them.
Quantity
Quantity is established by measurement, not by counting. Shore tanks are gauged before and after transfer; the vessel’s tanks are measured by ullage — the distance from the liquid surface to a fixed reference point — and converted to volume using calibration tables specific to that vessel.
Volume then has to be corrected to a reference temperature, because petroleum products expand and contract measurably with heat. A figure quoted without a temperature basis is not a figure. Once corrected and combined with density, volume becomes mass, which is what is usually invoiced.
The inspector will typically record both the shore figure and the vessel’s own figure, and note the difference. Which of the two governs is a contractual choice, made in advance and written down — arguing about it afterwards is a well-known way to lose money slowly.
Quality
Samples are drawn to defined procedures: from shore tanks, from the vessel’s tanks, and often from the transfer line during loading, so that the sample reflects the cargo as a whole rather than one convenient part of it. Individual samples are combined into a composite, and that composite is what is tested against the agreed specification.
Crucially, retained samples are sealed and kept for a period defined in the contract. If a dispute arises weeks later, there is something physical to go back to. A trade without retained samples has no way to settle a quality argument except by assertion.
The certificate of quantity and the certificate of quality are not formalities collected for the file. In most sale contracts the inspector’s determination at the load port is final and binding for invoicing purposes, save for fraud or manifest error.
That is the entire point. It converts “we say it was 30,000 tonnes of on-spec product” into a measurement a bank, a buyer and an arbitrator can all rely on.
Why the two ends rarely match exactly
A cargo loaded at 30,000 tonnes will not discharge at exactly 30,000 tonnes, and this is normal rather than sinister. Product clings to tank walls and lines, measurement itself has tolerances, and temperature conditions differ between the two ports.
What matters is whether the difference falls inside the tolerance the contract allows, and who carries it if it does not. Both of those belong in the contract before the vessel sails, not in an email afterwards.
Cost, and who appoints
Inspection cost is commonly shared equally between buyer and seller, which is the arrangement most consistent with the inspector being independent of both. Where one side appoints and pays alone, the other is entitled to appoint their own representative to attend.
A counterparty who resists independent inspection, or insists that only their own nominated inspector may attend, has told you something important. It appears on our list of warning signs for exactly that reason.
What “EN 590 10 ppm” pins down · FOB, CFR, CIF — who carries what
Inspection is step six of how a transaction runs at our desk, at load and again at discharge.
Every cargo, inspected at both ends
Tell us the product, the volume and the destination market, and the inspection regime will be named in the written offer alongside the specification.