All Post, Sourcing & Trade
The Seven Documents to Ask a Supplier For — and What Each One Actually Proves
The short answer
Seven documents, in this order: business licence, quality-system certificate, part-number cross-reference, test report, packaging specification, warranty terms, and payment details. Almost every buyer asks for the first two and stops. The order is what matters — each document only means something once the one before it checks out, and each one proves less than it appears to.
The table below is the whole article. The rest explains how to read it.
What each document proves, and what it does not
| Document | What it proves | What it does not prove | How to check it in five minutes |
|---|---|---|---|
| Business licence | A legal entity with that exact name exists and is registered | That it is the factory. Trading companies hold licences too | Match the legal name character-for-character against the invoice, the contract and the bank account holder |
| Quality-system certificate (IATF 16949 / ISO 9001) | The site named on it was audited to that standard, within the scope printed on it | That your part number falls inside that scope | Look the certificate number up in the issuing body’s public register, then read the scope line — not the logo |
| Part-number cross-reference | The supplier claims this part replaces that OEM number | That the part is dimensionally correct | Check the OEM number stamped on the original part, then confirm the mapping in a second, independent catalogue |
| Test report (dimensional / material) | The sampled units met the stated specification | That the units you receive will | Read the report date, the sample size, and whether your part number is actually named in it |
| Packaging specification (carton dimensions, weight, quantity) | How the goods are configured for shipment | That the packaging survives the crossing | Compare against the carton you actually receive, and against the basis used in your freight quote |
| Written warranty terms | What happens on failure, and who pays which freight | That the supplier will honour it | Confirm the claim route, the named legal entity, and the destination for a return |
| Payment details | Who you are paying | That the payee manufactures anything | Require the payee name to match the licence and the contract before money moves |
Why the order matters
Identity first. If the entity on the licence is not the entity on the invoice, nothing downstream is verifiable — you are collecting documents about a company you are not transacting with. This is the single most common failure, and it is invisible unless you compare the strings.
System second. A quality certificate is evidence about a management system at a named site within a stated scope. It is not evidence about a part. Two suppliers can both hold valid IATF 16949 certificates and one of them can still ship you the wrong heat treatment, because the certificate does not follow the part number.
Part third. The cross-reference is a claim, not a measurement. It is the cheapest document to fake and the most expensive to get wrong, because a wrong mapping produces a part that bolts on and fails later. If the open question is how much to commit before the mapping is proven, the MOQ comparison sets the three sourcing routes side by side.
Batch fourth. A test report is evidence about samples. The useful questions are who sampled, when, how many, and whether your part number appears in the document rather than in the covering email.
Logistics fifth. Packaging and carton data decide your freight basis. If the carton dimensions in the quote differ from the carton on the dock, your landed cost was wrong before the goods moved — the arithmetic in our landed-cost walkthrough starts from these numbers.
Remedy sixth. Warranty terms are only worth the entity that stands behind them and the freight rule attached to them. “Guaranteed” without a named entity and a return destination is a sentence, not a term.
Money last. Payment details are the point where a documentary error becomes a financial one. Verify the payee before you verify anything else you cannot recover.
The five-minute version
You have a PDF in hand and no time. Do these four things:
- Copy the legal name from the licence and paste it next to the invoice name. Any difference — a suffix, a different city, a parent company — is a question, not a detail.
- Take the certificate number to the issuing body’s public register. A certificate that does not resolve there is not a certificate.
- Read the scope line out loud. If it names a product family, a site, or a process that does not include your part, the certificate is about a different conversation.
- Ask for the carton dimensions and the gross weight per carton in writing. If the answer arrives as a photo of a label, ask again.
None of this requires a factory visit. All of it is cheaper than a wrong first order.
What is not on the list, and why
Three things buyers ask for that do not belong here:
- A factory video. It is unverifiable and easy to stage. Ask for the site address on the certificate instead and check that the address is a production site.
- A customer reference list. Names on a slide prove nothing you can check. Ask what the reference customer buys and in what annual volume; a real reference survives that question.
- A promise of exclusivity. It is a commercial term, not a verification step. Put it in the contract or leave it out.
A note on where POCYBER sits in this
The sourcing desk publishes the terms it works to: non-standard parts are quoted per part with no factory minimum, quotes come back within 48 hours through the trade channel, and transaction terms include FOB, EXW, DDP and global warehouse drop shipping. Ignition parts carry an 18-month warranty from delivery, and a failed part is replaced or refunded locally in the US — photo evidence is accepted, and the part does not travel back to China.
Those are the terms we will be held to. The seven documents above are what we expect to be held to as well. You can compare the published terms on the sourcing page and the trade programme terms before you send a request.
The bottom line
- Ask for seven documents, in order, and read each one for what it does not prove.
- The licence-to-invoice name match is the cheapest test you will ever run and the one most often skipped.
- A quality certificate is about a site and a scope, never about your part number.
- A cross-reference is a claim; the OEM number on the part is the evidence.
- Any document that cannot be resolved in a public register is decoration.
Frequently asked questions
Is an IATF 16949 certificate enough to trust a supplier?
No. It tells you a named site was audited to that standard within a printed scope. It does not tell you your part number is inside that scope, that the process ran on your batch, or that the entity you are paying is the entity that was audited. Use it as a filter, not a verdict.
How do I verify a supplier’s certificate?
Take the certificate number to the issuing certification body’s public register and confirm three things: the number resolves, the legal name matches the one on your invoice, and the scope covers the product and process you are buying. The IATF publishes a certificate database at iatfglobaloversight.org; ISO 9001 certificates are searchable through IAF CertSearch.
What if the supplier is a trading company, not a factory?
That is normal and not automatically a problem. What changes is which documents matter: the licence and payment details must match the entity you contract with, and the quality certificate must belong to the actual production site — ask for that site’s certificate separately, because a trader’s own ISO 9001 certificate says nothing about the factory behind it.
Which document catches the most problems?
In practice, the part-number cross-reference. It is cheap to produce, rarely independently checked, and a wrong mapping produces a part that installs correctly and fails early. Check the OEM number on the original part before you accept any mapping.
Do I need all seven for a small first order?
For a first order of 20 to 50 pieces, ask for all seven and expect the last three to be short. The cost of asking is one email; the cost of skipping the name match or the scope line is a lost order you cannot charge back.