What Is Pre-Shipment Inspection

Pre-shipment inspection (PSI) is the final check on an order before it ships. The inspector takes samples from the actual goods and checks the quantity, defects, dimensions, function, packaging, labels, accessories, and other requirements against the buyer’s approved documents.

A useful pre-shipment inspection should give the buyer enough information to make a clear decision: ship, hold, sort, repair, re-inspect, or reject.

Check Whether the Order Is Ready

Before booking the inspection, ask the supplier for these three numbers:

• Ordered quantity
• Finished quantity
• Packed quantity

Example A:

• Ordered: 8,000 units
• Finished: 8,000 units
• Packed: 6,800 units
• Packed rate: 85%

All 8,000 products are finished, so the inspector can check the products themselves. But 1,200 units are not in final packaging yet, so carton quantity, labels, packing method, and shipping marks are not fully covered.

Example B:

• Ordered: 10,000 units
• Finished: 6,000 units
• Packed: 5,800 units

In this case, 4,000 units have not been made yet. An inspection of the first 6,000 units cannot be treated as a final check of the whole 10,000-unit order.

If a large part of the order is still being made, a During Production Inspection is usually a better choice. JS Sourcing uses DUPRO during the 20–80% production stage, when there is still time to find and fix problems before the rest of the order is completed.

Use One Approved Inspection File

Give the inspector one set of approved documents:

• Purchase order
• Product specification
• Latest technical drawing
• Approved sample
• Bill of materials when needed
• Packaging specification
• Label artwork
• SKU and quantity list
• Test methods
• Defect list

Do not use a vague product description such as:

2-inch stainless steel valve, good quality.

Use details the inspector can actually check:

• Model: BV-200
• Nominal size: 2 inch
• Body material: CF8M
• Ball material: SS316
• Seat: PTFE
• Connection: NPT
• Working pressure: 1,000 PSI
• Handle: blue
• Body marking: logo + size + pressure rating
• 10 units per carton
• Maximum carton gross weight: 18 kg

Also check that everyone is using the same document version.

The inspector should not have to guess which number is correct. The buyer should confirm which drawing or specification is the final approved version before the inspection starts.

For custom products, these checks should start before mass production. A pre-production inspection can check materials, equipment, samples, tooling, and the production setup before the factory starts making the full order.

Count Finished and Packed Goods

This is a 5,000-unit order:

• Finished: 4,850 units, or 97%
• Packed: 4,700 units, or 94%
• Unfinished: 150 units
• Not yet packed: 300 units

Even if the inspected products pass the quality checks, the order still has a quantity problem. Product quality and order quantity should be checked separately.

For example, if a 12,000-unit order has only 11,760 finished units, the shortage is 240 units, or 2%. That shortage should be shown clearly in the report.

Also count:

• Master cartons
• Units per carton
• Colors
• Sizes
• Models
• Spare parts
• Accessories

Set Defect Rules Before Inspection

Decide before inspection which problems are critical, major, or minor.

The same defect can have a different level of risk on different products. A sharp edge on an industrial bracket is not the same as a sharp edge on a children’s product. Set the defect class based on the actual product and how it will be used.

For appearance problems, define the size and location instead of using words such as “bad” or “serious.”

Do not write:

No bad scratches.

Write:

No scratch longer than 5 mm on the front visible surface when viewed from approximately 50 cm under normal inspection lighting.

Example workmanship sample:

• Units inspected: 125
• Front-surface scratches: 6 units
• Loose screws: 3 units
• Paint defects: 4 units

Do not simply add these numbers and report 13 defective units. One product may have both a scratch and a loose screw. The report should make it clear whether it is counting separate defects or defective products.

Measure Critical Dimensions

Every important dimension should have a clear tolerance.

Requirement: 25.00 ± 0.10 mm

Allowed range: 24.90–25.10 mm

Sample 4 is 0.03 mm above the maximum allowed size.

For each important measurement, tell the inspector:

• Which tool to use
• Where to measure
• How many units to measure
• How many readings to take on each unit
• The minimum and maximum allowed values

A tape measure may be fine for checking the width of a table. It is not the right tool for checking a machined part with a tolerance of ±0.05 mm.

ISO 10012:2026 sets requirements for measurement management systems used to support reliable measurement results.^[1]

Example measurement plan:

• Requirement: sheet thickness 1.50 ± 0.05 mm
• Units measured: 5
• Points per unit: 2
• Total readings: 10
• Tool: suitable micrometer

Match Material Documents to the Batch

Check whether the material documents actually match the material used for the order.

Useful information may include:

• Material marking
• Heat number
• Batch number
• Material certificate
• Supplier material label
• Production record
• Thickness
• Weight

Example:

• Material certificate: Heat No. A12345
• Material bundle in factory: Heat No. B67890

The certificate may be real, but it does not prove that the material in front of the inspector came from that heat. The factory needs to explain the mismatch and provide records that link the material to the order.

Do not identify SS304, SS316, a plastic resin grade, fiber content, or chemical content just by looking at the product. A magnet or visual check may help spot an obvious difference, but it cannot prove the exact grade.

If the exact material composition matters, use the correct material test or laboratory test.

Test Functions That Affect Use

Focus on functions that can cause the customer to return the product, reject it, or fail to install it.

Do not tell the inspector only to “check function.” Write down how the test should be done.

For a load test, for example, specify:

• Load
• Where the load is applied
• How long the test lasts
• Number of samples
• Allowed deformation
• What counts as failure

Not every test needs the same sample size.

These are only example quantities. The actual number depends on the product, the risk, how long the test takes, customer requirements, and whether the test damages the product.

Check Packaging Against the Shipping Route

Inspect the products in their final packaging.

Check:

• Individual packaging
• Inner boxes
• Master cartons
• Foam
• Dividers
• Corner protection
• Carton sealing
• Strapping
• Pallets
• Carton dimensions
• Gross weight
• Units per carton

Example packing requirement:

• 5-layer export carton
• Individual foam sleeve
• Divider between every unit
• Top and bottom foam pads
• Maximum gross weight: 18 kg

Example inspection result:

• Cartons checked: 20
• Crushed corners: 4
• Cartons above 18 kg: 2
• Highest carton weight: 20.6 kg
• Carton missing internal divider: 1

If the goods are going by sea, also think about stacking, humidity, container movement, pallet handling, and repeated warehouse handling.

If a drop test is required, state how it should be done. ISO 2248:1985 covers vertical impact testing for complete, filled transport packages and uses set conditions such as drop height and package position.^[2]

A worker dropping one carton once from an unknown height is not the same as a defined packaging test.

Scan Labels and Count Accessories

Compare labels with the final approved artwork.

Check:

• Brand
• Model
• SKU
• Barcode
• Country-of-origin marking
• Warnings
• Carton marks
• Shipping marks
• Size and color labels
• Instruction manuals

For barcodes, do not only read the printed number. Scan them.

Example:

• Retail boxes checked: 30
• Printed barcode numbers correct: 30
• Barcodes scanned successfully: 27
• Failed scans: 3

All 30 printed numbers are correct, but three barcodes still fail because the print contrast is too low. That can still cause problems when the products reach a warehouse.

Also open sampled retail boxes and count the accessories.

Required set:

• Main product × 1
• USB-C cable × 1
• Wall bracket × 1
• Screw pack × 1
• User manual × 1

If two of 30 opened boxes are missing screw packs, ask the supplier to check the affected lot before shipment.

Set the AQL Plan Before Sampling

If the order will not receive a 100% inspection, agree on the sampling plan before the inspector arrives.

The current ISO 2859-1:2026 provides AQL-based sampling plans for inspection by attributes.^[3]

Record:

• Lot size
• Inspection level
• Sampling plan
• AQL for major defects
• AQL for minor defects
• Rule for critical defects
• Acceptance number
• Rejection number

AQL 2.5 does not mean that 2.5% of the shipment has been proved defective. It is one part of the sampling plan used to decide whether the inspected lot meets the agreed limit.

NIST describes acceptance sampling as checking a sample and using the result to accept or reject a lot instead of checking every unit.^[4]

Do not copy a sample size or Ac/Re number from another inspection report without checking:

• Lot size
• AQL
• Inspection level
• Sampling plan
• Standard edition

Cover Every SKU and Production Source

The green version makes up only 1% of this 5,000-unit order. If the sample is taken only according to total quantity, very few green units may be checked.

Give extra attention to SKUs that use different:

• Materials
• Colors
• Printing
• Components
• Packaging
• Production lines

The inspector should also take cartons from different parts of the warehouse. The factory should not prepare a small group of its best products in advance and use those as the inspection sample.

When it matters, cover different:

• Production lines
• Shifts
• Material batches
• Molds
• Mold cavities

For example, an eight-cavity injection mold may have one bad cavity while the other seven make acceptable parts. If all samples happen to come from the good cavities, the inspector may miss the repeated problem.

Read the Report by Numbers

The report should give the buyer enough detail to understand what happened without having to call the factory for an explanation.

Check that it shows:

• Ordered quantity
• Finished quantity
• Packed quantity
• Sample size
• Sampling method
• Critical defects
• Major defects
• Minor defects
• Measurements
• Test results
• Packaging results
• Label results
• Photos
• Tests not completed

Weak finding:

Product has scratches.

Useful finding:

8 of 125 inspected units had scratches longer than the agreed 10 mm limit on the front visible surface.

Weak finding:

Size wrong.

Useful finding:

Required hole spacing is 120 ± 0.5 mm. Five samples measured 121.1, 121.0, 120.8, 121.2, and 121.0 mm. All five were above the maximum allowed value of 120.5 mm.

Keep these results separate:

• PASS — the check was completed and the requirement was met
• FAIL — the check was completed and the requirement was not met
• NOT TESTED — the test was not done
• NOT AVAILABLE — the product, equipment, document, or sample was not available

A test that was not done is not a pass.

Stop Shipment for Critical Failures

Do not make the shipping decision from the final PASS/FAIL box alone.

Example:

• Order: 5,000 metal cabinets
• Finished: 5,000
• Packed: 4,750
• Workmanship sample: 200 units
• Major defective units: 7
• Minor defective units: 11
• Dimension sample: 20 units
• Lock test: 20 units
• Packaging check: 20 cartons
• Installation-critical dimension failures: 3 of 20

Three failures out of 20 measured units equal 15% of that dimension sample.

The workmanship result may still be within the agreed limit, but that does not mean the order should ship. First find out whether the wrong dimension is limited to those three units or affects a larger part of the production lot.

Hold the order when:

• A critical safety problem is found
• An important installation dimension fails
• A required test was not done
• The wrong material batch may have been used
• An important SKU was not inspected
• The order has a serious quantity shortage
• The packaging is not strong enough for shipment

A buyer can choose to accept a small, non-critical difference. If this happens, record the purchase order, SKU, quantity, exact difference, and whether the approval applies only to that shipment.

Fix the Lot, Then Re-Inspect

For repeated or widespread problems, use these four steps:

Example:

• First inspection: 125 units
• Units with unacceptable paint defects: 18
• Factory action: 100% sorting and repair
• Re-inspection: new random sample of 125 units
• Remaining minor paint defects: 2

A few supplier photos do not prove that thousands of products were sorted and repaired correctly.

Also check whether the repair created another problem. Repainting may remove scratches but create:

• Color differences
• Dust
• Masking marks
• Uneven coating
• Different surface gloss

Keep Compliance Testing Separate

Do not use a normal PSI report as proof of chemical composition or full legal compliance.

PSI can normally check:

• Visible workmanship
• Dimensions
• Basic function
• Packaging
• Labels
• Whether required documents are present
• Simple tests that can be done at the factory

Separate laboratory or compliance testing may be needed for:

• Lead
• Cadmium
• Phthalates
• Formaldehyde
• Food-contact migration
• Flammability
• Electrical safety
• EMC
• Material composition
• Other regulated properties

For U.S. general-use products covered by CPSC-enforced safety rules, the manufacturer or importer must issue the required General Certificate of Conformity based on the required testing. A normal PSI does not replace this responsibility.^[5]

If laboratory testing is important, record where the sample came from. For higher-risk products, the test sample can be taken from mass production and recorded with the SKU, batch number, selection date, and seal number.

Choose the Right Inspection Stage

Use more than one inspection stage when the order carries more risk.

Example:

• New factory
• Custom product
• Order value above USD 100,000
• Tight installation deadline
• Several important dimensions

In this situation, a factory audit, pre-production inspection, DUPRO, and PSI can each catch a different type of problem.

For a repeat order from a supplier with a good history, using the same material, tooling, drawing, and packaging, fewer inspection stages may be enough.

Set Time and Cost by Workload

Decide what needs to be checked before comparing inspection prices.

Inspection time depends on:

• Number of SKUs
• Sample size
• Number of dimensions
• Functional tests
• Assembly work
• Packaging tests
• Factory location
• Special equipment

A simple single-SKU order may fit into one inspector-day.

An order with:

• 20 SKUs
• 200-piece workmanship sample
• 20 dimensional samples
• 20 functional tests
• 5 assembly tests
• 20 carton checks

will take much more work than a simple visual check of one SKU.

Compare what the inspection price includes, not only the final amount.

Release Checklist

• Ordered, finished, and packed quantities have been checked.
• The latest drawing and artwork versions were used.
• Important SKUs were included in the sample.
• Critical, major, and minor defect rules were agreed before inspection.
• AQL and the sampling plan were set before inspection.
• Important dimensions were measured with suitable tools.
• Material documents match the actual batch when required.
• Important functions were tested.
• Packaging was checked in its final packed condition.
• Barcodes were scanned, not only read visually.
• Accessories were counted.
• Failed tests are clearly listed.
• Tests that were not done are clearly listed.
• Repairs and corrective work were checked when needed.
• No critical safety, fit, or function problem remains open.

Finally

Do not release an order just because the report says PASS. Check the numbers behind the result. For a 5,000-unit order, make sure the expected quantity is finished and packed, important SKUs were included in the sample, and key dimensions and functions passed. A workmanship sample may meet its AQL limit while a separate 20-piece dimension check still finds 3 parts that cannot be installed. Hold the shipment if an important requirement fails, a required test was not done, or repair work has not been checked. Ship only when the remaining problems are clear and acceptable.