A client of mine in California sent me a supplier he had found on his own. The brochure looked good, the specifications were plausible, and nothing suggested I should look twice. He asked me to visit them.
I never made the trip. Two checks — under five minutes each — told me what I needed, and the answer came down to one question: which factory were they planning to show me?
Check one: I added their WeChat. It was a different person.
My client had been dealing with this "factory" on WhatsApp. He forwarded me the salesperson's number, and in China, business runs on WeChat — so I added that number there.
The person who accepted was not the person my client had been talking to.
Alone, that proves nothing. But look at what it implies.
In a real factory, the export contact and the domestic contact are usually the same person. They know the product, the order and the schedule, and they use both apps because they carry the whole customer relationship.
Two different people on the two apps usually means the WhatsApp contact is an export salesperson — and the company behind them is an exporter, not a manufacturer. Trading companies work exactly this way: one person markets overseas, someone else handles everything domestic.
Check two: I asked for their location. It wasn't a factory.
I asked them to share a location pin — an entirely normal request in China.
What came back was not an industrial park. It was an office.
Here is the part most buyers get wrong: they sent it without hesitation. When the pin showed an office, they had an answer ready — "that's our office and showroom." They know the question is coming. The office is not a secret; it is the front door.
So the signal is not "the address is commercial" — plenty of legitimate companies have offices. The signal is that they described themselves as a manufacturer, yet the place they wanted me to come to was an office, with the factory visit left for later.
Which raises the only question that matters: if the factory visit happens later, which factory is it going to be?
The answer: the one they choose after they've sized you up
This is the part that took years on the factory floor to understand, and it appears in no supplier brochure.
An intermediary is rarely refusing to show you a factory. It is sequencing things differently.
What a manufacturer does — and what I do when I take a client to visit one: you go to the plant first. You walk the workshop, look at the profile stock and the cross-sections, watch the line. Then you sit down and talk price, terms and schedule. The factory comes first, because the factory is the business — there is nothing to arrange and nothing to decide.
What an intermediary does: you arrive at the office and you talk. Your drawings, your specifications, your quantities, your target price, your market, your timeline, your concerns. Only after that is the factory visit "arranged."
Why that order? Because by the time you finish talking, they know exactly what you need — which means they know exactly which plant to put in front of you. Maybe a partner factory, maybe one that matches your specification, maybe simply whatever is available this week and photographs well. From your side of the table they all look the same: a factory, a workshop, a production line. From theirs, it was a choice.
That is why the sequence matters more than any single signal. A manufacturer has no reason to talk before showing you production — the plant answers most of your questions by itself. An intermediary has every reason to talk first.
It shows up as: the visit doesn't match the brochure
One client ran straight into this. Before he flew to China, a salesperson showed him a factory — photographs, product range, production video, the full presentation.
When he arrived and was taken to see "the factory," it was not the one he had been shown. Not a different workshop in the same group, not a newer building — a different company's plant.
He was not angry that intermediaries exist. He was angry at being told something untrue, and he said so in blunt terms.
That is the real cost. The plant you think you are buying from and the plant you actually visited may be two different buildings — and nobody tells you which one your order will come from.
Six questions you can ask today
Before you invest more time with a Chinese supplier:
- Add their WhatsApp number on WeChat. One person on both apps, or two?
- Ask for a location pin. Industrial zone with factory buildings, or an office tower?
- Ask one technical question about how the product is built — wall thickness, hardware brand, how the thermal break strip is fixed. Do they answer from production knowledge, or deflect with "I'll check with the factory"?
- Ask to see production first — a live walk-through of the workshop, not a recording. This is the strongest signal: a manufacturer walks you into the workshop before anyone offers you tea.
- Ask which legal entity manufactures the goods, and whether that entity is the one quoting you.
- Watch the sequence. Did they want to talk before showing you the plant?
None of this needs a plane ticket. It needs only that you ask — and notice when an answer does not fit.
A note on why this matters
Trading companies are not a dirty word. They perform a real function: consolidating products, handling export paperwork, making it easier to deal with many suppliers at once.
The problem is not that a company is a trader. The problem is when it presents itself as a factory to win your trust — and then prices, controls quality and carries responsibility as an intermediary, while you believe you are dealing directly with the source.
That gap has consequences: a plant you never assessed, a specification you cannot verify, a schedule nobody fully controls. Knowing which one you are dealing with just lets you ask better questions.
The signals are everywhere
Those checks are only the easiest ones to run from a distance. Almost every step carries a small signal:
The quotation. A manufacturer's quote is specific — profile series, wall thickness, glass build-up, hardware brand, and what is excluded. A single total price with generic descriptions suggests the person quoting does not work from production knowledge.
The photographs. Production photos have context: machine beds, work in progress, profile stock, pallets, someone else's order in the background. Catalogue photography does not.
The paper trail. Compare four names — the quotation, the invoice, the bank account, and the entity that manufactures. When they do not line up, you are not dealing with the source.
The payment terms. An intermediary often has to fund the factory before you pay, and that pressure shows up in how much they want up front.
And the answers that drift. Ask the same question twice, weeks apart. A manufacturer gives the same answer, because it is a fact.
None of these is conclusive alone, and the point is not to memorise a checklist.
The point is to notice when a detail does not fit — and then ask one more question.
That instinct is the part that is not in any textbook. It comes from walking through enough workshops and watching enough orders go wrong to know what "normal" looks like — and therefore what does not. It cannot be looked up, because it is not general knowledge. It is what you have actually seen.
Which is also why this series is written from visits, not from research.
Next in this series: what these checks look like on the ground — the order I walk a client through on a real factory visit, and why we go to the workshop before anyone offers us a seat.
Series: Spotting a Real Factory
- Part 1 (this article): The WeChat Test — remote checks, and why the sequence matters
- Part 2: PA66 vs PVC — and how to check
- Part 3: Thermal break continuity — where the break is lost in a frame