AQL Inspections Explained: A Simple Guide for UK Importers Buying from China

Quick answer: AQL stands for Acceptable Quality Limit. It is the sampling method most inspection companies in China use to decide whether a production run passes or fails. An inspector picks a random sample based on your order size, counts the defects and compares them with agreed limits. A common setting for consumer goods is zero critical defects, AQL 2.5 for major defects and AQL 4.0 for minor defects. For an order of 3,201 to 10,000 units, that means checking 200 units and failing the batch if 11 or more major defects are found.

When you order from a factory in China, you cannot check every unit yourself. A pre-shipment inspection based on AQL gives you a fair, standard way to judge a whole order from a sample, before you pay the balance and before the goods leave the factory. This guide explains how AQL works in plain English, how to read the tables and how to choose the right levels for your products.

What AQL means

AQL sampling comes from the international standard ISO 2859-1, which is closely matched by the American standard ANSI/ASQ Z1.4. It answers two questions:

• How many units should be checked from an order of this size?
• How many defects can be found in that sample before the order fails?

AQL does not mean the factory is allowed to send you a set percentage of faulty goods. It is a statistical cut-off for the sample. Any defective units found should still be repaired or replaced. For a wider view of how inspections fit into your sourcing, read our quality control inspections guide for UK buyers.

The three defect types

Before an inspection, you and the inspector agree how defects are classed:

• Critical defects could cause harm or break safety rules, for example a sharp edge on a child's toy or exposed wiring. Most buyers accept zero.
• Major defects would likely lead to a return or complaint, for example a broken zip, wrong colour or a product that does not work.
• Minor defects are small flaws that most customers might not notice, for example a loose thread or a light mark on the inside of a box.

Write examples of each defect type into a defect list for your product. Clear examples stop arguments later about whether a fault is major or minor.

How to read an AQL table

Reading the tables takes two steps.

Step 1: Find the sample size from your order size

The standard sets inspection levels. General Inspection Level II is the usual default. Your order quantity (the lot size) gives a code letter, and the code letter gives a sample size.

Step 2: Find the accept and reject numbers

For each AQL value, the table shows an accept number and a reject number. If the defects found are at or below the accept number, that defect type passes. If they reach the reject number, it fails.

Here are the most common rows at General Inspection Level II, normal inspection, single sampling:

• 281 to 500 units: check 50. Major defects at AQL 2.5: accept 3, reject 4. Minor defects at AQL 4.0: accept 5, reject 6.
• 501 to 1,200 units: check 80. Major defects at AQL 2.5: accept 5, reject 6. Minor defects at AQL 4.0: accept 7, reject 8.
• 1,201 to 3,200 units: check 125. Major defects at AQL 2.5: accept 7, reject 8. Minor defects at AQL 4.0: accept 10, reject 11.
• 3,201 to 10,000 units: check 200. Major defects at AQL 2.5: accept 10, reject 11. Minor defects at AQL 4.0: accept 14, reject 15.
• 10,001 to 35,000 units: check 315. Major defects at AQL 2.5: accept 14, reject 15. Minor defects at AQL 4.0: accept 21, reject 22.

Example: You order 5,000 phone cases. The inspector checks 200 at random from across the cartons. They find 0 critical, 8 major and 16 minor defects. Majors pass (8 is within the limit of 10), but minors fail (16 is over the limit of 14). The batch fails overall, and you can ask the factory to sort and rework before shipping.

Choosing the right AQL for your product

There is no single right answer, but these points help:

• Safety-related products such as toys, electricals and baby items should have zero critical defects and often a tighter major limit, such as AQL 1.5 or 1.0.
• Premium or gift products may justify a tighter minor limit, because small marks matter more to buyers.
• Low-cost promotional items can often work with the common 2.5 and 4.0 settings.
• Tighter limits cost more to meet, so agree them with the factory before the order, not after.

Your limits should match your approved sample. If you are still at the sampling stage, see our guide to getting product samples from China first.

What an AQL inspection checks

A typical pre-shipment inspection happens when at least 80% of the order is finished and packed. As well as counting defects, the inspector usually checks:

• Quantity and carton count against your order
• Product size, weight, colour and materials against your specification and approved sample
• Function tests, such as switching on electrical items or opening and closing zips
• Labels, barcodes, warnings and markings
• Packaging, carton strength and shipping marks
• Photos of the products, packing and any defects found

Our guide on how to quality check products before they leave China walks through each check in more detail.

Put AQL in your purchase order

An inspection only protects you if the factory has agreed to it in writing. In your purchase order, include:

• The standard (ISO 2859-1), inspection level and AQL values for critical, major and minor defects
• Your defect list and approved sample reference
• What happens if the batch fails, such as sorting, rework and a re-inspection at the factory's cost
• That the balance payment is only made after a passed inspection

Linking the final payment to a passed inspection gives you leverage. Our guide on how to pay Chinese suppliers safely explains how to structure deposits and balances.

What to do when an inspection fails

1. Read the report and photos carefully to see which defects caused the fail.
2. Ask the factory for a root cause and a plan to fix it.
3. Agree a full sort of the batch, with defective units repaired or replaced.
4. Book a re-inspection before you release the balance.

If the same problems keep coming back, it may be a sign to review the supplier. Our guide on fixing quality issues with your manufacturer covers the next steps, and a factory audit can show whether the factory has the systems to improve.

Frequently asked questions

What does AQL 2.5 mean?

It is the limit used to set the accept and reject numbers for a defect type. With AQL 2.5 at Level II, an order of 3,201 to 10,000 units has a sample of 200 and fails at 11 or more defects of that type.

Is AQL the same as a percentage of faulty goods?

Not quite. It is a statistical limit used on the sample to decide whether the whole batch passes. Any faulty units found should still be fixed or replaced.

Which inspection level should I use?

General Inspection Level II is the usual default. Level I uses smaller samples and Level III uses larger ones. Special levels use small samples for tests where checking many units is not practical, such as tests that destroy the product.

When should the inspection happen?

Pre-shipment inspections usually take place once at least 80% of the order is finished and packed, so the inspector can sample from the full batch.

Who pays for a re-inspection if the batch fails?

That depends on your agreement. Many buyers write into the purchase order that the factory pays for re-inspection after a failed result.

Can Epic arrange AQL inspections for me?

Yes. Our quality control and factory audit service includes inspections in China with clear reports and photos before you pay the balance.

Check your goods before they ship

Epic Sourcing UK helps small businesses source from China with vetted suppliers, agreed quality standards and inspections at the factory. Book a free chat to plan quality checks for your next order.