How to Check a Chinese Aluminum Supplier Before You Send a Deposit

Most buyers run these checks in the wrong order. Price first, three quotes compared second, and only then — with a supplier already chosen — the question of whether the company is real and the metal comes from where the certificate says. The deposit usually goes out before that last question is answered.

Reverse it. Everything below takes about two days, and none of it requires flying to China.

1. Read the business license, not the homepage

Ask for the business license and read the registered scope of business printed on it. For an aluminum supplier, one of two phrases usually appears:

• Manufacture of non-ferrous metal alloys — the company is licensed to produce metal.
• Sale of metal materials — the company trades.

There is nothing wrong with the second one. Most aluminum leaving China is sold by trading companies, because mills are set up to pour tonnage, not to answer eleven emails about a three-tonne mixed order.

What you are looking for is the mismatch: a rolling mill on the homepage, the word sale on the license. That is not fraud by itself. But it tells you who answers when something goes wrong, and it decides whether the 3.1 certificate will carry the mill's letterhead or theirs.

2. Ask for the customs registration number

Every exporting company in China is registered with customs and holds a 10-digit customs registration code. Ask for it. Then ask for two export declarations from the last six months, with the buyer name blacked out if they prefer.

Three things to look at:

• Declared description. Does it match what you are buying, or is every line just "aluminum products"?
• Declared value. A declaration at well under the market price for 6061-T6 plate tells you how they handle paperwork in general.
• Destination ports. A supplier who has never shipped to Rotterdam can still be good — but they will be learning on your order, and you should price that in.

A company that cannot produce a customs code within a day is not exporting.

3. Ask which line, which width

The standard answer is that they run the production line themselves. Follow it with one question: what is the maximum coil width on the line?

Anyone who actually rolls metal knows this to the millimeter — 1,450 mm, 1,650 mm, 2,050 mm — because it decides whether your order fits on the line at all. Anyone repeating marketing copy says "custom sizes available".

We publish regions rather than mill names, because allocation flexibility is part of what a buyer is paying for, and under NDA we hand over the audit reports. Other suppliers will name the mill on the first email. Both are workable answers. A vague answer is not.

4. Test the inspection story with one question

Ask: how do you measure thickness on a coil, and when was the gauge last calibrated?

A real answer has specifics in it. Micrometer at three points across the width, every coil, recorded on the inspection sheet, gauge checked every six months against a calibration block.

A decorative answer sounds like "we have a professional QC team and strict quality control". That is not a lie. It is just not information.

5. Samples: ask whether it is the same heat

A sample cut from a stock coil tells you the alloy is roughly right. It tells you nothing about the production run.

Ask two things: will the sample and the production order come from the same heat number, and will the sample arrive with that heat number on its certificate?

If the sample is free and lands in four days, but nobody can tell you which heat it came from, you have received a brochure made of metal.

6. Check who signs the 3.1 certificate

EN 10204 3.1 is issued by the manufacturer's own inspection department, tied to a specific heat number, carrying the test results from that heat. A trading company cannot issue one. It can only pass one through.

Ask for a redacted 3.1 from a previous shipment and look at the letterhead.

• Mill letterhead, heat number, test results — real.
• Trader letterhead with a "3.1" header — a 2.2 with ambitions. Your customer's incoming inspection will find out, usually after the container is unloaded.

7. The bank details must match the license

This is the check that prevents most actual losses, and it has nothing to do with aluminum.

The beneficiary name on the proforma invoice should match the company on the business license. If the account sits in Hong Kong under a different entity, if the beneficiary is a personal name, or if the bank details "change" by email after the contract is signed — stop and pick up the phone.

Email interception is common enough in this trade that a changed bank detail is now the single most reliable fraud signal there is.

What a good supplier sounds like

Short answers with numbers in them. A line width, a heat number, a calibration date, a port, a lead time counted in working days.

They will also tell you what they cannot do: a width they cannot roll, a temper they will not guarantee on 0.2 mm foil, an alloy they would rather buy in than make. A supplier who says yes to everything in the first email has either not read it or does not intend to be held to it.

Red flags that are not red flags

• Being a trading company. That is what most exporters in this business are. What matters is whether they control inspection and documents.
• Refusing to name the mill before an NDA. Normal. Mills do not want their names used to shop prices around.
• A small office. Aluminum moves by phone and container, not by floor space.
• A slow first reply. Time zones. Two days is normal. Two weeks is a decision.

The two-day checklist

Two days of asking, before a deposit of five or six figures. The arithmetic is not close.