AQL 2.5 final inspection: what it checks and how to read the result

What does AQL mean in garment inspection?

AQL stands for Acceptable Quality Limit: the worst average defect rate that a buyer is prepared to treat as acceptable. It does not mean 2.5% of your goods may be defective in every carton. It is a statistical sampling plan. The inspector draws a random sample from a finished lot, counts defects, and compares the count with a published accept number. If the count is at or below it, the lot passes; if above it, the lot fails.

The plans come from ISO 2859-1 (the same tables as ANSI/ASQ Z1.4). They are used because checking every piece is expensive and still misses defects, whereas random sampling gives a defined confidence on the lot as a whole.

What are critical, major and minor defects?

• Critical. A defect that makes the garment unsafe or illegal to sell, such as a broken needle fragment, a choking hazard on children’s wear, or banned substances. The usual limit is zero.
• Major. A defect that makes the garment unsaleable or noticeably wrong: a hole, a broken seam, a wrong size, a visible stain, the wrong colour.
• Minor. A defect that departs from specification but would not stop most customers from buying: a loose thread, slightly uneven topstitching, a small crease.

Apparel buyers commonly set AQL 0 for critical, 2.5 for major and 4.0 for minor defects. These are common defaults, not rules: write the levels you want into the purchase order, because a stricter level means more rejections and a looser one more returns.

How big is the sample for my lot size?

Sample size depends on lot size and the inspection level. Most garment inspections use General Inspection Level II. The table shows the sample size and the maximum defects allowed for a pass at AQL 2.5 (major) and AQL 4.0 (minor).

Worked example: a 3,000-piece lot falls in the 1,201–3,200 row. The inspector checks 125 pieces at random across cartons and sizes. At AQL 2.5 the lot passes with up to 7 major defects and fails at 8 or more.

What does an inspector actually check on the day?

1. Lot readiness. Is at least 80% of the order packed? (A common rule for a final random inspection.) Inspection on a half-packed lot says little.
2. Random carton selection across the whole lot, then random pieces from each carton, across all sizes and colours.
3. Visual and workmanship. Seams, stitching, stains, colour shading, print or embroidery quality, loose threads, symmetry.
4. Measurements. A set of pieces is measured against the chart and tolerances in the tech pack.
5. Fit and function. Zips, buttons, snaps and drawcords tested; garments checked on a mannequin or fit model where agreed.
6. Labels and packaging. Fibre content, care and origin labels, hangtags, barcodes, polybag warnings, carton marks and carton weight.
7. Safety checks. Metal detection and needle policy where required; tests such as carton drop and colour fastness as specified.
8. Report. Counts of defects by class, photographs, pass/fail against the AQL, and any corrective actions.

What happens if a lot fails?

A fail is not the end. Typical outcomes are: 100% sorting and repair by the factory, followed by re-inspection at the factory’s cost; partial release of cartons that pass a second sample; or, if defects are systemic, a negotiated allowance. Agree the consequences in the contract before production: who pays for re-inspection, how many days a re-inspection can take, and whether the shipping date moves.

Keep final payment tied to a pass. A balance due only after a clean third-party inspection is the single strongest protection for a buyer who cannot visit the factory. See how to pay safely.