Last updated: October 2026 · By the PandaRoads team in China
The three defect classes
| Class | Definition | Typical AQL | Example |
|---|---|---|---|
| Critical | Unsafe / violates regulation / unusable | 0 | Exposed live wiring, missing safety label |
| Major | Impairs function or saleability; buyer would reject | 2.5 | Wrong color, broken seam, non-working button |
| Minor | Cosmetic; unlikely to affect use or sale | 4.0 | Small scratch, slight print misalignment |
How the sample size is chosen
- Lot size + inspection level (General II is default) → a sample-size code letter from ISO 2859-1.
- The code letter → a sample quantity and accept/reject numbers for each AQL.
- Example shape: a 3,000-unit lot at Level II samples a few hundred units; exceeding the accept number for majors fails the lot.
What “fail” means for your money
- A failed sample = do not ship / do not release the 70% balance until rework and a re-inspection pass.
- Put the AQL levels and the inspection right (who inspects, when, against which specs) in the contract before the deposit, or the inspection is advisory only.
- Inspection before loading is far cheaper than a dispute after arrival — see pre-shipment inspection.
Who should run the inspection
An independent third party (or your agent), never the factory’s own QC alone. Our on-site inspection is $239 per day with same-day photo/video evidence; remote document/spec checks are $129 per request. Cost detail: inspection cost guide.
Frequently Asked Questions
Is AQL 2.5 always the right level?
It is the common default for consumer goods majors. Safety-critical or regulated products use tighter (or zero) critical limits; cheap promotional goods sometimes relax minors. Set levels per product risk, in the contract.
Does a passed AQL inspection mean zero defects?
No. AQL accepts a statistically tolerable defect rate; it is a sampling method, not 100% checking. A passed lot can still contain defects within the accepted limit.
Can the factory refuse an AQL inspection?
A legitimate factory accepts independent inspection when it is in the contract. Refusal, or insisting on their own QC only, is a red flag — see supplier scams.