What is the difference?
A certificate of analysis reports test results for a defined lot against a specification, on the producer’s or a laboratory’s letterhead. Third-party inspection is a surveyor’s report of what was observed against a written scope. A clean COA does not prove the bags on the quay are that lot. An inspection does not automatically re-run every chemical test.
What each document can and cannot prove
Use this as a buyer checklist. The contract still has to name which document binds which claim.
| Question | COA typically | Inspection, if in the agreed scope |
|---|---|---|
| Lab results vs specification | Yes, for the sampled lot and methods named | Only if sampling and testing are in the nomination |
| Lot identity on paper | Batch, heat or silo if stated | Marks, seals, numbers the surveyor saw |
| Quantity / tally | No | May include if nominated |
| Packing, marks, condition | No | May include if nominated |
| Loading or discharge supervision | No | May include if nominated |
| Who issued it | Producer or appointed lab | Named inspection company |
Sampling, location and issuer
A COA is only as good as the sample and the method. Ask where the sample was drawn and whether the lot on the certificate can be tied to marks on the cargo. Inspection houses describe pre-shipment work as attending at mill, plant, warehouse or port against instructions. SGS and Intertek publish typical activity lists; those lists are examples of possible scope, not TTC appointments and not a default for every file. See https://www.sgs.com/en/services/pre-shipment-inspection and https://www.intertek.com/government/
Certificate of quality and certificate of quantity
Some contracts use “certificate of quality” for a quality document that is not a full COA, and “certificate of quantity” for a weight or tally document. Do not treat those labels as interchangeable with a COA or with a survey. Read the definition in the contract.
Final and binding wording
If quality is “final at load based on the COA”, a later destination test may have little contractual weight. If quantity is “final as per independent survey”, the COA will not settle a shortage. Write which document is binding for which dispute, who appoints the inspector, who pays, and what happens if COA and inspection disagree. Inspection scope is contract-dependent. Do not imply every third-party inspection covers sampling, quantity, packing and loading.
When both are needed
Often: a lot COA for the specification, plus a surveyor for quantity, packing or loading. A COA cannot replace pre-shipment inspection merely because the PDF is clean. If lots on the COA do not match the bill of lading, you have a documentation problem as well as a quality problem.
In an RFQ, say whether you require a producer COA only, a named inspector, or both, and at which stage. TTC coordinates inspection where the contract requires it. TTC does not appoint SGS, Intertek or any other house by default.
Primary sources
SGS pre-shipment inspection overview: https://www.sgs.com/en/services/pre-shipment-inspection
Intertek government and trade inspections: https://www.intertek.com/government/