Contracts and Quality Control in China: Golden Sample, PO, and Inspections

Once you’ve picked your supplier and agreed on price, there’s a step many importers underestimate: putting everything in writing and setting up a clear quality control system. This is exactly where some of the most expensive mistakes in the whole import process happen.

In this guide, we’ll walk through everything from the golden sample and purchase order to inspection types and the difference between quality control and quality assurance.

Golden sample and dimensional tolerances

Never start mass production without a perfect sample in your hands. Factories will often say they’ll “fix the last details during production”. Do not agree to this.

You need to have a sample that matches your specifications exactly before you sign the purchase order and before the factory starts mass production.

This final, approved sample is called the golden sample.

Best practice is to have two golden samples made:

• Keep one with you, so you can compare it to production during and after shipment.
• Sign the second one and send it back to the factory – this is their internal quality reference for the whole batch.

Dimensional tolerances

Not every product needs millimetre‑level precision, but many items must stay within a defined tolerance range. A pillow, for example, doesn’t need to be accurate to the millimetre – the customer won’t notice a 0.5 cm difference. But if you’re importing mechanical parts or components that fit into other products, tolerances are critical.

Define tolerances clearly and add them to your specification and contract. This gives you clear quality standards and basically does half the work needed for your inspection checklist.

What to define before ordering – the Purchase Order (PO)

Chinese factories have a strong tendency to say “Yes, can!” to almost everything – even to things they don’t really plan or are not able to do. To avoid this, put all your requirements into a single, clear list and confirm it with the factory manager.

Your pre‑order terms list should include:

• Unit price
• Order quantity
• Payment terms (typical: 30% deposit, 70% after inspection)
• Product specifications and labelling requirements
• Packing requirements
• Tooling and mould cost and ownership (if applicable)
• Dimensional tolerances (if applicable)
• Mass production lead times
• Penalty clauses for late delivery
• Quality criteria: defect classification (“critical”, “major”, “minor”) and agreed AQL level
• No unauthorised outsourcing to other factories
• Product warranty terms
• Your right to perform unannounced factory visits

Purchase Order (PO) format

For most importers, a detailed, well‑written PO is enough, as long as it includes all of the points above. It should contain:

• Your full company details and logo
• Complete supplier information
• A unique PO number and date
• A list of products with quantities, unit prices, and total amount

After you send the PO, the supplier will issue a Proforma Invoice (PI). Check that every detail in the PI matches your PO exactly. Both documents should be signed by the legal representatives of both parties, and the factory should stamp each page with their official red company stamp.

Do you really need a formal contract?

There is a common myth that contracts in China are worthless. In reality, the Chinese legal system has developed significantly and is more advanced than most people think. The real problem is that a contract written by a lawyer who doesn’t specialise in Chinese business law usually has very little legal weight in a Chinese court.

When a contract is not strictly necessary

For new importers and smaller orders, a full formal contract is often not worth the cost. That money is usually better invested in stock or marketing. A well‑structured PO with clear terms and conditions is often enough.

When a contract is a must

There are two situations where you should definitely hire a lawyer who specialises in Chinese business law:

1. When the order value is high
2. When you are protecting intellectual property (your design, patent, or brand)

How to avoid contract traps

If you work with a sourcing company based in China, they can prepare the contract and legally represent you directly with the supplier. A local agent is usually in a much better position to put legal pressure on the supplier if they don’t respect the agreed terms.

The main value of a contract is not just legal protection – it is first and foremost a strong communication tool. It helps avoid misunderstandings and gives the supplier a very clear picture of your expectations and how serious you are about quality and deadlines.

Quality control – why it’s critical when importing from China

If you import from China, you need to understand one key point: production problems must be solved before the goods leave the factory. Once the container is on the water, your options become very limited.

Regular, independent quality control also has another important function: it encourages the factory to maintain higher standards. Simply put – if the supplier knows you are checking, they are much less likely to cut corners on materials or production.

Types of quality inspections

Pre‑shipment inspection is the most common type of inspection and is enough for most importers. If problems are found, the importer has the right to withhold the final payment until the issues are fixed.

Here is a quick overview of the main inspection types we use:

• Pre‑production inspection – checking raw materials and components before production starts
• During‑production inspection – checking while 30–50% of the goods are finished
• Pre‑shipment inspection – the most common one; checking finished goods before loading
• Container loading inspection – supervising the physical loading of goods into the container
• Product testing and certification – checking compliance with standards (CE, RoHS, etc.)
• Laboratory testing – for chemical composition, mechanical properties, and similar parameters

You can find more details about inspection types and procedures in the article Reduce product defects and recalls with effective quality control in China.

QA vs QC – the difference and why you need both

Quality Control (QC) vs Quality Assurance (QA)

These are two different functions that often get mixed up:

• QC (Quality Control) – finds defects, deviations, and wrong specifications in the finished goods. QC doesn’t redesign the product or change the spec – it simply checks whether the goods match the PO and agreed requirements.
• QA (Quality Assurance) – happens before mass production. It confirms that all sample details are correct and that everything in the spec is properly defined before the factory starts producing thousands of units.

How to combine them

QA is your checkpoint before you enter mass production – confirmation that everything is set up correctly. QC is your checkpoint at the end – confirmation that the factory actually made the goods according to plan. Use them together, in this order:

1. QA → approval of the golden sample and specifications
2. Mass production
3. QC → inspection of finished goods before shipment

Quality control starts with supplier selection

This is something many new importers don’t realise: no amount of QC can turn a bad factory into a good one. If you chose the cheapest supplier, they will probably use cheaper materials to protect their margin – and no inspection can change that.

You get consistent quality only one way:

The right manufacturer + Quality Assurance (QA) report + Quality Control (QC) inspection

Frequently asked questions

What is a golden sample and why is it a must before mass production?

A golden sample is the final approved sample that matches your specifications exactly and serves as the reference for both you and the factory. Without an approved golden sample, you should not start mass production, because the risk of repeating the same mistake across the whole batch is very high.

Is a Purchase Order enough or do I need a formal contract?

For new importers and smaller orders, a well‑structured PO with clear terms, specs, deadlines, and AQL criteria is usually enough. A formal contract becomes necessary when order values are high or when you need to protect intellectual property (design, patent, brand), in which case it’s wise to work with a lawyer specialised in Chinese business law.

What is the practical difference between QA and QC?

QA (Quality Assurance) is done before mass production and covers approval of the golden sample, specifications, and production conditions. QC (Quality Control) is done after production and focuses on detecting defects in finished goods and checking whether they match the PO and agreed AQL standard before shipment.

When is it essential to hire an independent inspection company in China?

Independent inspection is especially important when you work with a new supplier, when the shipment value is high, or when product specifications are strict (for example, mechanical parts or certified products). A pre‑shipment inspection lets you find and fix issues before the container leaves China, because after arrival your options are much more limited.

Can quality control (QC) compensate for a bad supplier choice?

No – QC cannot “fix” a bad manufacturer; it only reveals the problems in finished goods. The best results come from combining a good supplier choice with a clear QA system (golden sample and specs) and regular QC inspections before shipment.

Need professional inspection for your goods in China? Contact us – our QC team can support you at every stage of production.

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