Our inspection contract says "AQL 2.5 per ISO 2859-1". Which edition applies now?
An AQL figure only works when buyer, factory and inspector use the same sampling scheme. With ISO 2859-1 revised in 2026, name the edition in writing.
Our third-party inspection contract for knit tops says "AQL 2.5 major, 4.0 minor per ISO 2859-1". A colleague says the standard changed this year. Do we need to update the contract, and what should we check with the inspection company?
Main answer
Yes, it is worth updating the wording. ISO lists ISO 2859-1:1999 as withdrawn in January 2026 and revised by ISO 2859-1:2026. A contract that only says "per ISO 2859-1" no longer makes clear which edition the inspector should use. Ask your inspection company which edition its procedures and sampling tables follow, and write that edition into the contract and the purchase order.
What the AQL actually means
The 1999 edition defines the acceptance quality limit as the worst tolerable process average when a continuing series of lots is submitted for acceptance sampling. It also notes that the AQL does not suggest a desirable quality level. That is a useful point for buyers. An AQL of 2.5 is a decision rule for accepting or rejecting a lot from a sample. It is not a promise that only 2.5 percent of garments will have defects.
The scheme also includes switching rules between normal, tightened and reduced inspection, based on recent lot results. Many apparel inspection contracts quietly use normal inspection only. If you intend to apply switching rules, or not, say so.
What to agree with the inspector
Beyond the edition, three things decide what an inspection actually checks. The first is the inspection level, which, with lot size, sets the sample size. The second is the AQL for each defect class. The third, and the one most often left vague, is the defect classification itself: which faults count as critical, major and minor for this product. A list for knit tops might classify an open seam as major and a loose thread as minor. That list belongs to your product, not to the standard.
Ask the inspection company to send its defect list and sampling table for your order before the first inspection, and confirm them with the factory. Then everyone is measuring against the same rules.
Keep earlier results comparable
If the revised edition changes anything in the sampling tables or rules your inspector uses, results before and after the change may not be directly comparable. Note the edition on every inspection report so that your supplier scorecard compares like with like.
The short version: name the edition, the inspection level, the AQLs and the defect list in one place, and have the factory confirm it.
Sources and further reading
Standards and rules are summarised from their published scope or official guidance. Use the current edition and confirm requirements for your market.
Three perspectives on this question
Purchasing perspective
I add the edition, inspection level and AQLs to the purchase order, not only the inspection contract. The factory signs the PO, not the inspector's contract, so that is where it binds. I also state who pays for re-inspection if a lot fails.
Merchandising perspective
The defect list is where product knowledge goes. For printed tees I would make print placement and print defects explicit majors, because those are what customers return. A generic apparel list often treats them too lightly.
QC perspective
Before the first inspection under new wording, I would run one inspection with the inspector and the factory QC together to calibrate the defect classification. Most disputes I see are about whether a fault is major or minor, not about the sample size.
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