AQL Explained Simply: How to Read a China Inspection Report

A China inspection report often looks like a table full of unfamiliar letters and numbers: AQL 2.5, Ac 5 / Re 6, sampling level II. Most buyers treat it as a formality to sign off on — “inspection passed.” In reality, those numbers hold the answer to the question that actually matters: how much defective product could realistically be in the batch arriving at your site next month. Here is what AQL means, how the sample size is calculated, and how to read a report in five minutes without an engineering background.

What AQL is and why it exists

AQL (Acceptable Quality Limit) is a statistical quality-control method defined by the international standard ISO 2859-1 (identical in the US to ANSI/ASQ Z1.4). The point is that an inspector does not open and check every single unit in a batch of 3,000 chairs — that would take weeks and cost more than the goods themselves. Instead, a strictly defined sample is pulled from the batch according to a table, only that sample is checked, and the result is used to draw a statistically valid conclusion about the entire batch.

AQL is not “the percentage of defects you have to accept.” It is a pre-agreed threshold: if the sample contains fewer defects than the allowed number, the entire batch is accepted; if it contains more, the entire batch is rejected, and the manufacturer must re-sort or rework the goods at its own expense. That is why AQL is fixed in the contract or invoice before production starts, not once the container is already sitting at the port — see the full inspection process in quality control in China.

How the sample size is calculated

Sample size does not depend on a percentage — it depends on two parameters: the lot size (number of units) and the inspection level. Most non-food goods use General Inspection Level II, a balance between speed and accuracy. The larger the batch, the larger the sample, but the growth is not proportional: a batch of 3,000 units does not require a sample ten times larger than a batch of 300.

A batch of 2,500 boxes of porcelain tile and a batch of 1,250 boxes are checked with the exact same sample — 125 units — because both fall inside the 1,201-3,200 range. That is the statistical logic of AQL: no manual percentage math, just a fixed number pulled from the table.

Three defect classes: critical, major, minor

Before the sample is counted, defects are sorted by severity — and each class has its own AQL threshold:

• Critical — makes the product unsafe or entirely unusable (sharp edges on children’s furniture, an electrical short, missing safety markings). The acceptable level is always AQL 0 — not a single such defect is allowed anywhere in the sample.
• Major — noticeably impairs function or appearance but is not dangerous: a misaligned cabinet door, a chip on a visible countertop edge, a sagging recliner mechanism. Standard threshold: AQL 2.5.
• Minor — a small deviation an ordinary buyer might not notice: a slightly uneven stitch, a faint shade difference on a hidden surface. Standard threshold: AQL 4.0.

For furniture, tile, sanitaryware, and other interior products, the 0 / 2.5 / 4.0 combination is the industry default, and it is worth locking into the specification before production begins.

The AQL table: how to read Ac and Re

The key notations on any inspection report are Ac (Accept) and Re (Reject) — two numbers. The batch is accepted if the number of defects found is at or below Ac, and rejected if it reaches Re or higher.

Example: a batch of 2,000 restaurant chairs (sample of 125, code K). The inspector found 6 major defects (a sagging rocking mechanism, a chipped frame) and 9 minor ones (small stitching irregularities). On majors — 6 is at or below Ac 7, so the batch passes; on minors — 9 is below Ac 10, so it passes too. The overall verdict on the whole batch is “passed,” even though the report lists every single defect found in plain language.

How to read an inspection report in 5 minutes

A typical PSI report (Pre-Shipment Inspection) is structured the same way across most agencies:

1. General information — lot size, inspection date and location, the sampling level and AQL applied.
2. Measurement and functional test results — conformity of dimensions to spec (usually ±2-3 mm tolerance for furniture), strength, stability, and mechanism function checks.
3. Defect list by category — critical / major / minor, with photos of each instance and how many sampled units it appeared on.
4. Final verdict — Pass, Fail, or Pending (at the buyer’s discretion), with a direct comparison of defects found against the Ac/Re thresholds.

The main rule for reading a report: do not stop at the “Passed” stamp in the header — scroll down to the defect table and check exactly what was found and on how many units. AQL is a statistical tool, not a guarantee of zero problems: a batch can formally pass inspection and still contain a defect that matters to you but was never written into the inspection checklist beforehand. That is why it is worth agreeing not just on the AQL numbers, but on the exact list of parameters to check — alongside a golden sample the inspector uses as the benchmark.

When AQL sampling is not enough

For product categories with a direct safety risk — electrical components, children’s furniture, glass in shower enclosures — a 100% check of a specific parameter (every glass panel for chips, for instance) is often added on top of standard AQL sampling. This is worth discussing separately with the inspector and budgeting for on sensitive categories.

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Want to be sure a batch actually matches the specification, not just a formal AQL pass? We run production inspections against an agreed checklist with a photo report on every defect found — so you see the real picture before the container ships. Dream View’s fixed commission is 10% of the order value — details on the China sourcing agent page.