Failed inspection: what to do when the lot does not pass?

A failed lot has not shipped yet: this is the best moment to act. Identify the defects at fault in the report, then ask the supplier to sort or rework the goods before a re-inspection, at its expense if the AQL and third-party inspection are in the purchase order.

Getting goods inspected, in practice · By Guerric Laspougeas · Published 5 October 2026

What “failed lot” means

During a final random inspection, the inspector checks a sample drawn at random according to AQL and counts the defects, classified as critical, major and minor. The lot fails as soon as one type of defect reaches its limit. For an order of 5,000 pieces at inspection level II, the sample is 200 pieces and the lot fails from (the AQL calculator gives these thresholds for any other quantity):

A lot can also fail on other points: incomplete quantity, a failed function or safety test, missing marking, non-compliant packaging. The inspector records and documents; they never decide the fate of the production. You decide, report in hand.

Step 1: read the report before calling the supplier

Before any negotiation, pin down the problem:

• Which defects make the lot fail? A single critical defect is enough, whatever the rest. If it is majors, which ones come up most?
• Systematic or random? The same defect on many pieces (a dimension out of tolerance, a wrong colour) comes from the process: sorting will not be enough. Varied, scattered defects point rather to the care taken in manufacturing.
• Concentrated or spread out? If the defects are in certain cartons, a line or shift may be at fault, and sorting can be targeted.
• Visible or not? An appearance defect can be sorted by eye; a function or safety defect requires a test on every piece.

Step 2: choose the right response

Step 3: negotiate with the supplier

Your position depends mainly on what was written before the order. If the purchase order sets the AQL levels, the reference sample and third-party inspection, the rejection is not your opinion against theirs: it is the application of a rule they accepted. You can then legitimately ask them to rework the goods and pay for the re-inspection.

• Send the report quickly, with the list of defects and the response you expect (sorting, rework or new production).
• Ask for the root cause and the corrective action, in writing, not just a promise to “be careful”.
• Agree together on the re-inspection date and its impact on the shipping date.
• Do not pay the balance before a passed re-inspection: it is your main lever.

Step 4: the re-inspection

Once sorting or rework is finished, the lot is inspected again. It is booked like a first inspection, with a 48-hour minimum lead time. A few rules for it to make sense:

• it covers the whole lot, not just the reworked cartons;
• it uses the same AQL limits, or a higher inspection level: after a failure, the level is raised to look at more pieces;
• it checks first the defects that made the first inspection fail.

Keep some margin in your schedule: our guide on the booking lead time for an inspection explains how to place the final inspection so you can react.

Stopping it happening again

• Write the rules before the order: AQL, a signed reference sample, the defect list, re-inspection at the supplier’s expense if the lot fails.
• Inspect earlier on the next order: a during production inspection or production monitoring spots defects while they can still be corrected, until results become stable again.
• Go back to the cause: if failures repeat, a technical audit of the factory looks at the quality system, not just the product.

To understand how these checks fit together, read our complete guide to quality control in China.