Supplier verification is not about distrust. It is about establishing that a supplier has the equipment, the process and the people to do what they promise, at the volume you need. Photographs and certificates are easy to obtain. The checks below are not.
We run this same checklist on every supplier who wants our business, and we publish it here because a buyer who knows how to check will send us fewer unqualified enquiries and better ones.
What to verify and how
Production capability
Ask what the monthly output is and in what unit — pieces, cartons, or containers. The unit tells you a great deal. A supplier quoting \”200 containers per month\” is making a capacity claim; one quoting \”50 tons per month\” is telling you their output is weight-limited, which for glass means a different constraint entirely.
Ask how many production lines and which ones can produce your specific jar. A plant with six lines may only be able to run two of them for pressed glass of your type.
Mould ownership and capability
For custom work, ask whether moulds are made in-house or outsourced. In-house moulds usually mean faster iteration and better control. Ask for the mould room — a functioning mould shop has grinding, polishing and measurement equipment, and it is normally visibly busy.
Decoration capability in-house
This is where claims break down most often. Suppliers often describe silk-screen, frosting, spraying, plating and engraving as capabilities when several are subcontracted. It does not disqualify them, but it changes your quality control approach and your lead time.
Ask which processes are in-house and which are subcontracted. If subcontracted, ask where and whether you can visit.
Annealing capability
Annealing ovens consume significant energy and space. A supplier serious about quality has them. Ask about the annealing cycle used and the temperature profile. This is the question most likely to produce a straight answer from a serious supplier, because it is a real capability rather than a marketing point.
Testing and laboratory
Ask what testing is done in-house versus at an external laboratory. Requests for lead and cadmium migration, thermal shock and food contact compliance are routine. A supplier with a small laboratory handling basic checks and an established relationship with an accredited external lab is normal and acceptable.
QC process
Ask what inspection happens at each stage: incoming material, during production, at finishing, and pre-shipment. Ask to see a pre-shipment inspection report from a previous order, with the customer\’s name removed.
A supplier with no inspection report has no inspection process worth the name.
Export experience and documentation
Ask which markets they ship to regularly and request an example of a commercial invoice and packing list. Documentation quality tells you how much experience they have with your destination, and it is a good predictor of how smoothly clearance will go.
Ask whether they are the exporter of record or work through an agent. If an agent is involved, ask who signs the contract, whose name appears on the bill of lading, and whose bank receives payment. All three should be coherent and should be documented.
Verifiable third-party checks
- Business registration. Verify the company name and registration number in the Chinese business registry. Confirm the registered address is a real operating location.
- Business licence. Ask for a copy. Confirm the name matches the quotation and the bank account exactly.
- Export records. Ask for evidence of previous export shipments — an export declaration or bill of lading with customer details removed.
- Third-party inspection. For a first significant order, pay for an independent inspection company. This is the strongest verification available and is well worth the cost.
- Video walkthrough. Ask for a live video call walking through the production floor and the warehouse. Live video is difficult to fake, and asking for it does not damage the relationship with a serious supplier.
Warning signs
- Reluctance to show the production floor, or a walkthrough that is clearly pre-recorded
- Inability to state monthly capacity in specific units
- Every process claimed as in-house
- No inspection report available, for any order
- Pressure to skip inspection to save time
- Inconsistent information between quotation, invoice and bank account
- Reluctance to sign the specification and quality standard
- Any refusal to allow third-party inspection, on a first order
One or two items on this list may be explainable. A pattern of them is not.
The relationship test
After verification, the first small order is the real test. Place it with the agreed specification, agreed inspection standard and agreed payment terms. Then observe: does communication happen without chasing, are problems raised early, is documentation delivered as promised?
A supplier that meets a small order cleanly is worth building a long relationship with. One that gets a small order right but a large one wrong will cost you far more than the price difference saved.
Why we publish our own verification checklist
We are a glass manufacturer, not a trading company. That distinction matters commercially and it is worth being explicit about why.
When you buy from a trading intermediary, the entity on your contract, the entity on your bill of lading, the entity receiving your payment and the factory making your goods can be four different parties. Each handover adds a margin and a place where your specification can be quietly reinterpreted. You are paying for coordination you cannot see.
Buying from the factory removes a layer. You speak to the people running the production line. Your specification, your quality standard and your complaint go to the same organisation that has to solve them. When something goes wrong, there is nobody to pass it to.
The checks described in this article are the ones we would run on any supplier, applied to ourselves:
- Monthly output stated in specific units. Not a range, not a vague figure. We state it in pieces and containers so you can verify it independently.
- Decoration processes stated honestly. In-house and subcontracted are named separately, with lead-time impact for each. We do not claim capabilities we have not committed to.
- Annealing as a documented cycle. Temperature range and duration, with records. This is the quality question that matters most and it is the one most often skipped.
- Inspection reports available. From previous orders, with customer names removed. A supplier with no inspection report has no inspection process.
- Export documentation sample. Request one and you will receive it.
- Third-party inspection welcome. On any order, including the first. If a supplier objects to independent inspection, that tells you everything.
We are based in Shandong and welcome buyers who want to see the production floor before placing an order. For a first significant order we would encourage it — talk to us first, arrange a visit, and judge the line for yourself. A supplier who is confident in their operation has no reason to decline.
Ask us for our production capability documentation, QC process and reference samples. We will tell you plainly what we can and cannot do. Request the details.