Quality Control & Inspections: Catching Problems Before They Ship

Quality problems discovered at your warehouse are expensive. Quality problems discovered at the factory cost a fraction of that. The entire purpose of quality control in China is to catch failures before they get on a ship.

This guide covers the inspection types you need to know, how AQL sampling works, what inspections cost, and how to handle it when problems show up.

The Three Types of Inspections

Pre-Production Inspection (PPI)

A pre-production inspection happens before manufacturing starts. The inspector checks that the factory has the right raw materials, components, and tooling on hand to build your product to spec.

This is the most overlooked inspection type. Most importers skip it. That’s a mistake.

A bad material discovered before production saves you weeks and money. The same bad material discovered after 10,000 units are built creates a nightmare. PPIs typically cost $250-350 and take half a day.

During-Production Inspection (DPI)

Also called an in-process or mid-production inspection. The inspector visits when 20-30% of the order is finished. They pull samples off the line and check them against your product spec sheet.

DPIs catch problems while there’s still time to fix them. If a component is wrong or a dimension is off, the factory can correct the remaining 70-80% of the order before the mistake compounds.

DPIs are especially important for large orders and new supplier relationships. Budget $250-350 per inspector per day.

Pre-Shipment Inspection (PSI)

This is the inspection most importers know about. It happens when 80-100% of production is finished and ready to ship.

The inspector pulls a random sample from the finished goods according to AQL tables, checks each unit against your spec sheet, tests functions, measures dimensions, and reviews packaging and labeling. You get a written report with photos within 24-48 hours.

If the inspection passes, you release final payment and the goods ship. If it fails, you decide: rework, partial acceptance, or rejection.

A pre-shipment inspection typically costs $250-350 for one man-day at most factories in China. QIMA’s published rate for Zone A (which includes mainland China) is around $309 per man-day. Most inspections finish in one day.

Inspection Companies: Who to Use

Four companies handle the majority of third-party inspections in China.

QIMA is the most buyer-friendly option. Book online, transparent all-inclusive pricing, 24-48 hour report turnaround. Good for small to mid-size importers who want predictable costs. Roughly $309/day in China.

SGS is the world’s largest inspection company. More enterprise-focused, slower to quote, but extremely thorough. Good for regulated industries or if your retail partners require SGS certificates.

V-Trust has a strong China focus, competitive pricing often in the $200-300 range, and a solid reputation among importers sourcing electronics and consumer goods. Good option for regular inspection programs.

Bureau Veritas is a large multinational, similar to SGS. Strong in regulated product categories. More complex onboarding for smaller buyers.

For most importers buying electronics from China, QIMA or V-Trust are the practical choices. Book directly through their websites. Don’t let your supplier recommend or arrange the inspection company. You want independence.

Understanding AQL Sampling Standards

AQL stands for Acceptable Quality Limit. It’s an internationally recognized sampling system (ISO 2859-1, also published as ANSI/ASQ Z1.4 in the US) that tells you how many units to inspect from a batch and how many defects you can accept before rejecting the shipment.

Most consumer electronics inspections use this standard setup:

Critical defects: AQL 0 – Zero tolerance. Any critical defect (safety hazard, complete non-function) means automatic rejection.
Major defects: AQL 2.5 – Functional issues, incorrect specs, significant cosmetic damage. A small number is tolerable; above the limit means rejection.
Minor defects: AQL 4.0 – Small cosmetic flaws most customers won’t notice or won’t return. Higher tolerance allowed.

For an order of 2,000 units at General Inspection Level II (the standard), the inspector samples 125 units. For AQL 2.5 major defects, the acceptance number is 7. If more than 7 of those 125 units have major defects, the inspection fails.

These numbers exist because inspecting 100% of production is impractical. The AQL system is statistically designed to give you confidence that the whole batch meets your standards based on the sample.

What Goes in a Product Spec Sheet

Your inspector can only check what you define. A vague spec sheet produces a useless inspection.

A good product spec sheet for electronics includes:

Exact dimensions and weight (with tolerances)
Component specifications (battery capacity, chip model, connector type)
Function checklist (every button, mode, and feature tested)
Visual quality standards (photos of acceptable and unacceptable finishes)
Packaging specifications (box dimensions, printing, inserts)
Labeling requirements (what must appear on the unit and box)
Required certifications visible on packaging (FCC, CE, UL, etc.)
Country of origin markings if required

Send this document to your supplier before production starts. Have them sign it. This is the legal definition of what you ordered, and it’s what the inspector uses to evaluate whether production passes.

For electronics specifically, check our FCC and UL compliance guide to make sure your spec sheet includes the right certification requirements.

Remote vs On-Site Inspections

Remote inspections, where the supplier’s team uses a live video call to walk an inspector through the product, became more common after 2020. They cost less, often $150-200, and can be scheduled faster.

They’re better than nothing. But they’re significantly weaker than on-site inspections.

A remote inspector relies on what the supplier shows them. An on-site inspector pulls units randomly from sealed cartons, chooses which units to test, and can ask workers direct questions. The independence matters.

Use remote inspections only for:

Very low-value orders where on-site cost doesn’t make sense
Established supplier relationships with a strong track record
Quick checks during production when a full DPI isn’t needed

For any meaningful order over $3,000-5,000, pay for on-site. The $300 inspection fee is nothing compared to what bad goods cost you.

What Happens When Inspectors Find Problems

An inspection report that shows defects above your AQL threshold means you have decisions to make.

Option 1: Reject and rework. The factory fixes the defective units and you schedule a re-inspection. Re-inspection costs another $250-350. You pay for it. Budget the time: rework plus re-inspection usually adds 2-4 weeks.

Option 2: Negotiate a price reduction. If defects are minor or cosmetic and you can sell the goods anyway, you can accept the shipment with a discount to account for the defect rate. This requires negotiation and typically works better with established suppliers.

Option 3: Full rejection. You refuse the shipment. This creates a dispute with your supplier and requires either replacement production or recovery of your payment. This is where your contract terms and payment method matter enormously. See the payment methods guide for how to structure payments to protect yourself in this situation.

Option 4: Partial acceptance. Sort the goods. Accept passing units, reject defective ones. Works if defects are concentrated in identifiable lots.

The most common outcome from a failed inspection is option 1 with a rework. Communicate clearly, get a written rework plan, and schedule re-inspection before releasing final payment.

Building a Quality Control Program

If you’re sourcing consistently from China, one-off inspections get expensive and inconsistent. A quality control program treats inspection as a system.

The basics of a solid QC program:

Approve spec sheets before every production run
Run DPIs on all new suppliers and large orders
Run PSIs on every shipment for the first six months
After a supplier passes 5-6 consecutive inspections, you can reduce to spot-check frequency
Track defect rates over time and use them in supplier negotiations

Some importers use a sourcing agent or third-party QC firm to manage this ongoing. That costs $500-1,000 per month for a managed program. For high-volume importing, the math usually works out.

Frequently Asked Questions

How much does a pre-shipment inspection in China cost? Most pre-shipment inspections in China cost $250-350 per man-day, which covers most factories. QIMA charges approximately $309 per man-day in China, inclusive of travel, report writing, and administrative costs. Most PSIs complete in one day.

What is AQL 2.5 and what does it mean for my inspection? AQL 2.5 is the acceptable quality limit for major defects in most consumer goods inspections. For a batch of 2,000 units inspected at General Level II, it means the inspector samples 125 units and accepts the shipment if 7 or fewer have major defects. Above 7 fails the inspection.

Can my supplier arrange the inspection? Never let your supplier choose or contact the inspection company on your behalf. The inspection must be independent to have any value. Book directly with QIMA, SGS, V-Trust, or Bureau Veritas using the factory’s address. Give the factory a heads-up on timing, but not control over the process.

What’s the difference between a factory audit and a product inspection? A factory audit evaluates the supplier’s capabilities, certifications, quality management systems, and facilities. A product inspection evaluates finished goods against your product specifications. You typically do a factory audit once (before placing an order) and product inspections on every shipment.

What should I do if my goods fail a pre-shipment inspection? Don’t release final payment. Contact your supplier with the inspection report and request a rework plan in writing. Get a timeline commitment. Schedule a re-inspection after rework. If the supplier refuses to rework or disputes the findings, escalate through your payment method (Trade Assurance or Letter of Credit) to protect your funds.

Do I need inspections for small orders? For orders under $1,000-2,000, inspection cost relative to order value is hard to justify. Instead, use Trade Assurance for payment protection and order samples from production before approving the full run. For orders over $3,000, the math on inspections almost always favors paying for one.