What does AQL 2.5 mean?

AQL 2.5 means that in a batch of 500 units inspected, you accept up to 10 major defects or 14 minor defects. More than that and the entire batch fails inspection. AQL 2.5 is the most common standard for consumer goods — apparel, electronics, toys, household items.

What's the difference between AQL 2.5 and 4.0?

AQL 4.0 is looser — it accepts more defects. Use it for cheap promotional items where a few defects don't matter. AQL 2.5 is the standard for retail-quality consumer goods. AQL 1.5 or 1.0 is for premium or safety-critical products. Lower number = stricter = fewer defects accepted.

How many pieces need to be inspected for AQL?

Not all of them. AQL uses sampling. For a batch of 500-1,000 units, you inspect 80 pieces at AQL 2.5. For 1,001-3,000, inspect 125. The sample size is determined by the lot size and inspection level — not a percentage of the order.

AQL Inspection Explained: What Every Importer Needs to Know Before Paying a Chinese Factory

You ordered 1,000 units. The factory says everything is fine. How many do you actually check before paying?

You can’t check all 1,000. You don’t have time. AQL — Acceptable Quality Level — tells you exactly how many to inspect and how many defects you can accept before rejecting the entire batch.

The Numbers — What They Mean

AQL is an international standard (ISO 2859). It’s a statistical sampling method. You don’t check every piece. You check a random sample. Based on what you find, you accept or reject the batch.

AQL 2.5 means: in the sample, you accept a small number of defects. If there are more, the whole batch fails. This is the standard for consumer goods sold at retail.

AQL 4.0 is looser. Used for cheap promotional items. Free pens handed out at a trade show? AQL 4.0 is fine. Products customers pay for? AQL 2.5 minimum.

AQL 1.0 or 1.5 is for premium goods. Safety-critical components. Medical devices. Products where one defect could hurt someone.

How Many to Inspect

Lot Size	Sample Size (Level II)
51-90	13
91-150	20
151-280	32
281-500	50
501-1,200	80
1,201-3,200	125
3,201-10,000	200

At AQL 2.5 for a batch of 500 units: inspect 80 random pieces. If you find 3 or fewer major defects, accept. If you find 4 or more, reject or require 100% rework.

Three Defect Types

Critical: The product is dangerous or illegal. One critical defect rejects the entire batch. No exceptions.

Major: The customer probably won’t accept it. A broken zipper. A screen with dead pixels. A shirt with a visible stain. These count toward your AQL limit.

Minor: Small imperfection. A loose thread. Slightly off-color packaging. The product still works and looks fine. These also count but at a higher allowance.

Using AQL in Your Contract

Write this in your PI or purchase contract:

“Inspection standard: ANSI/ASQ Z1.4, Level II, AQL 2.5 for major defects, AQL 4.0 for minor defects. Zero critical defects.”

If the factory pushes back on putting AQL in the contract, ask yourself why. A factory that’s confident in their quality doesn’t fear inspection. I inspect your goods before you pay the balance →

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