2026-10-12 · JCH Design & Manufacturing

Pre-shipment inspection: what the visit checks, how the sample is set, and what a fail looks like

One inspector, one day, a sample of cartons on a table. Whether it protects you is decided before the visit: the sample size, the defect list, the reference sample, and what happens on a fail.

Filed under Line watch and quality control

Short answer: A pre-shipment inspection is a check of your finished goods at the factory, done when most of the order is made and packed, before the balance is paid and before anything is loaded. An inspector pulls a random sample sized by a sampling standard, checks it against your approved sample, drawing and packing spec, and reports pass or fail. It is the last point where fixing a problem is still cheap.

A pre-shipment inspection is the check most importers have heard of and few set up well. The visit itself is simple: one inspector, one day, a sample of cartons opened on a table. What decides whether it protects you is everything agreed before the inspector arrives: the sample size, the defect list, the reference sample, and what happens if the lot fails. This note covers when to book a pre-shipment inspection, how the sample is set, what the visit checks, what a failed result looks like, and the mistakes that let bad lots through anyway.

What a pre-shipment inspection is, and when to book it

The timing is the part people get wrong. QIMA, one of the large third-party inspection firms, describes its pre-shipment inspection as an on-site examination "when 80% of your production order is complete," and says it "should be booked when your production is 80% finished and packing has begun." Book it earlier and there is not enough finished, packed product to sample. Book it after the last carton is sealed and the container is booked, and every correction turns into a delay.

Brushed stainless steel cabinet shells stacked on pallets in a factory, a finished lot waiting to be checked and packed — A finished lot on pallets. The pre-shipment sample comes from stock like this, drawn at random, not from a pile the factory chose.

Three things should be true before the inspector goes in:

Most of the lot is finished and packed, so the sample can be drawn from real export cartons, not from a pile the factory picked.
The balance is still unpaid. The inspection is your leverage. Once the money has moved, a failed report is just a document. The payment terms note covers how to tie the balance to a passed report.
The factory knows the criteria in writing: the AQL, the defect list and the reference sample. A surprise standard on inspection day starts an argument, not a fix.

How the sample size is set: AQL and inspection level

Nobody opens every carton. The inspector draws a random sample using the tables in ISO 2859-1 or its American twin, ANSI/ASQ Z1.4. ASQ describes Z1.4 as "an acceptance sampling system to be used with switching rules on a continuing stream of lots for Acceptance Quality Limit (AQL) specified." The current ISO edition is ISO 2859-1:2026; ANSI's overview of it says the scheme puts "economic and psychological pressure of lot non-acceptance" on the producer while "providing an upper limit for the risk to the consumer of accepting the occasional poor lot."

Three inputs set the plan: the lot size, the inspection level, and the AQL for each defect class. QIMA's AQL guide walks through a worked case: a lot of 4,000 units at General Inspection Level II gives code letter L, and "Code letter L at AQL 2.5 requires a sample of 200 units. If 10 or fewer units fail, the batch passes. If 11 or more fail, the batch is rejected." You can run your own numbers with our AQL calculator before you write them into the purchase order.

Defects are graded, and each grade gets its own limit. QIMA's summary is the common one: critical defects are "safety or compliance failures" and "AQL for critical defects is typically 0"; major defects affect function or appearance enough to cause a return; minor defects are small cosmetic issues. It also notes that "AQL 2.5 is the most common standard for general consumer goods," with 1.0 used for higher-risk categories and 4.0 where minor cosmetic defects are acceptable.

Input	What it controls	Typical consumer-goods setting
Inspection level	How many units are pulled	General Level II
AQL, critical	Safety and compliance defects	0, none accepted
AQL, major	Defects likely to cause a return	2.5
AQL, minor	Small cosmetic defects	4.0

What the inspector checks

A pre-shipment inspection checklist should be written for the product, but the categories are standard. QIMA's list for a PSI covers quantities of finished and packed goods; colors, style and construction; artwork and labels; workmanship; dimensions and unit weight; functional tests; and packing, including "export carton dimensions and weights" and "shipping marks on cartons."

In practice, a useful checklist covers:

Quantity. Finished, packed and still in production, against the order. A short count is a finding, not a footnote.
Product against the approved sample. Color, finish, fit and every feature on the drawing. The reference has to be a signed physical sample; the golden sample note explains why a sample alone does not hold a lot to standard.
Critical dimensions. The handful that decide fit or function, measured on a sub-sample, not all 200 units.
Function. Whatever the product is for: it switches on, the lid seals, the zipper runs, the hinge holds.
Labels and compliance marks. Country of origin, warnings, barcodes, care labels, all as specified.
Packing. Inner packs, carton strength, carton count and weights, and carton markings. The shipping marks note lists what belongs on each carton.

What a failed result looks like

A fail is a count, not an opinion: more major or minor defects in the sample than the accept number allows, or any critical defect at all. A good report lists every defect with a photo, the count by class, and a clear pass or fail against the AQL you set.

A long factory warehouse aisle with steel frames shrink-wrapped in red racks, staged before loading — Goods staged for loading. Once it looks like this, a failed lot means unwrapping, sorting and a second visit.

What happens next should already be in the purchase order. The usual path is that the factory sorts or reworks the lot, then a re-inspection is booked; QIMA notes that many clients request a re-inspection after corrective action. Agree in advance who pays for that second visit. A simple rule is that the supplier pays when its lot fails, which also gives it a reason to check its own work before the first visit.

A pre-shipment inspection also has limits. QIMA states plainly that a PSI "evaluates the finished goods visually and functionally" and does not replace laboratory testing. If the product needs chemical, electrical or safety testing, book an accredited lab separately. It is also not a factory audit: it judges this lot, not whether the supplier can make the next one.

Mistakes that let bad lots through

Only checking at the end. By the time 80% is packed, a design or material problem is in every carton. Catch it at first article and during production, then use the pre-shipment visit to confirm. That is how step 9 of our process is built.
Letting the factory pick the cartons. The sample must be random, drawn by the inspector from packed stock.
No written defect list. "Good quality" cannot fail a lot. A list of what counts as critical, major and minor can.
An inspector who answers to the factory. QIMA's point holds for anyone: when the factory's own team does the sampling, "the incentive is to pass, not to find defects."
Paying the balance before the report. Then the report is for your files, not for the factory.

How JCH handles it

Every order JCH runs is checked four times: incoming material, first article, in-process, and a pre-shipment check of the lot, sampled at AQL 2.5 to 4.0 as the product requires. Jack's own inspectors do the work, with third-party inspection companies brought in when needed. To set up an inspection plan for your next order, send us the order details.

Straight answers

What is a pre-shipment inspection?

A pre-shipment inspection is a check of finished goods at the factory before they ship. An inspector draws a random sample from packed stock using ISO 2859-1 or ANSI/ASQ Z1.4 tables and checks quantity, workmanship, dimensions, function, labels and packing against your approved sample and specification, then reports pass or fail.

When should a pre-shipment inspection be done?

When at least about 80% of the order is finished and packing has begun, and before the balance is paid. Earlier, there is not enough packed product to sample; later, every correction delays the shipment.

How many units are inspected?

It depends on lot size, inspection level and AQL. For example, a 4,000-unit lot at General Inspection Level II gives code letter L, which means a sample of 200 units; at AQL 2.5 the lot passes with 10 or fewer defective units and fails at 11.

What AQL should I use?

A common setting for consumer goods is 0 for critical defects, 2.5 for major and 4.0 for minor. Higher-risk products often use 1.0 for major defects. Write the levels into the purchase order before production starts.

What happens if the inspection fails?

The factory sorts or reworks the lot and a re-inspection is booked. Agree before the order who pays for the re-inspection; a simple rule is that the supplier pays when its lot fails.