Pre-shipment inspection and AQL explained
A pre-shipment inspection checks a random sample of finished, packed goods before you pay the balance. The sample size and pass/fail limits come from ISO 2859-1 (AQL). For example, a lot of 3,000 units at General Inspection Level II means inspecting 125 units; at AQL 2.5 the lot passes with up to 7 major defects.
By the Sino Vorex team · Updated
What a pre-shipment inspection is
A pre-shipment inspection (PSI) is a check of the finished goods at the factory, carried out when at least 80% of the order is produced and packed. It is the last point at which the factory can still fix problems cheaply, and the last point at which you have leverage, because the balance is usually not yet paid.
The four inspection types
| Inspection | When | Purpose |
|---|---|---|
| Pre-production (PPI) | Before production | Check materials and components; confirm the specification is understood |
| During production (DUPRO) | About 20–60% produced | Catch recurring defects while the line can still be corrected |
| Pre-shipment (PSI) | 80–100% produced and packed | Check quantity, quality and packaging before the balance is paid |
| Container loading check | During loading | Confirm the right goods and quantity are loaded, in good condition |
What AQL means
AQL stands for Acceptance Quality Limit. Under ISO 2859-1 (equivalent to ANSI/ASQ Z1.4), an inspector checks a random sample whose size depends on the lot size and the inspection level. The AQL sets how many defective units the sample may contain before the lot fails.
Defects are classed in three groups, each with its own AQL:
- Critical: unsafe, or breaks the law in your market (e.g. a sharp edge on a child's product). Usually zero tolerance.
- Major: likely to cause a return or complaint (e.g. a product that does not work, a visible stain). AQL 2.5 is common.
- Minor: a small departure from the specification that most customers would accept (e.g. a short loose thread). AQL 4.0 is common.
General Inspection Level II is the usual default. Level I uses smaller samples; Level III larger ones.
AQL table: sample sizes and limits
| Lot size (units) | Sample size | Major, AQL 2.5 (accept / reject) | Minor, AQL 4.0 (accept / reject) |
|---|---|---|---|
| 151–280 | 32 | 2 / 3 | 3 / 4 |
| 281–500 | 50 | 3 / 4 | 5 / 6 |
| 501–1,200 | 80 | 5 / 6 | 7 / 8 |
| 1,201–3,200 | 125 | 7 / 8 | 10 / 11 |
| 3,201–10,000 | 200 | 10 / 11 | 14 / 15 |
| 10,001–35,000 | 315 | 14 / 15 | 21 / 22 |
Example: a lot of 5,000 units falls in the 3,201–10,000 band, so the inspector checks 200 units. The lot passes for major defects with 10 or fewer, and fails at 11. Any critical defect normally fails the lot.
What a pre-shipment inspection checks
- Quantity: finished and packed units against the order.
- Workmanship: visual defects, compared with the approved sample.
- Specification: measurements, weight, materials and colour.
- Function and safety: tests suited to the product, such as operation, assembly or seam strength.
- Packaging and labelling: retail packaging, barcodes, labels, inserts and carton marks.
- Cartons: dimensions, weight and a drop test.
Reading the inspection report
A useful report gives a clear result (pass, fail or pending), the defect counts by class against the AQL limits, photos of every defect, measurements, and test results. A report that simply says "passed", with no photos or numbers, gives you little to act on.
When goods fail
Do not ship and do not pay the balance. Ask the factory to sort the goods, rework or replace the defective units, and then re-inspect. To make this straightforward, put three terms into your purchase contract before production starts:
- The balance is due only after a passed inspection.
- The factory pays for any re-inspection after a failed one.
- The approved sample is the reference for quality.
Getting an inspection in China
Book the inspection about a week before the goods are ready, and send the inspector your specification and a photo of the approved sample. We carry out pre-shipment inspections with photo and video reports for any supplier in China.
Frequently asked questions
Which AQL should I use?
For most consumer goods: critical 0, major 2.5 and minor 4.0. Use a stricter level, such as major 1.0 or 1.5, for high-value or safety-sensitive products.
Does passing AQL mean there are no defects?
No. AQL sampling accepts a small, defined risk of defects in the whole lot. A pass means the defect rate in the sample was within the limit you set.
Can an inspection replace lab testing?
No. Certification tests such as CE, UKCA or CPSIA are carried out by accredited laboratories. An inspection checks that production matches the specification and the tested sample.