The four services
Factory audit (supplier verification): an inspector visits the facility and checks licence, ownership, capacity, equipment, quality system and social compliance. US$300–600. Use before the first order.
During-production inspection (DUPRO): at 20–50% completion, checking that materials, workmanship and early units match the approved sample. US$250–350. Use on first orders and custom products — defects caught here are fixable.
Pre-shipment inspection (PSI): when 100% is produced and at least 80% packed. Random sampling to AQL (usually 2.5 major / 4.0 minor), function tests, measurements, packaging and labelling checks. US$250–350 per man-day. Use on every order; make the balance payment conditional on a pass.
Container loading check: verifying quantity, carton condition and container seal at loading. US$250–300. Use for high-value or theft-prone goods.
Writing the brief
Inspectors check against what you give them. Provide the spec sheet, approved sample photos, labelling and packaging requirements, the list of function tests, your defect classification (what counts as critical, major, minor) and the AQL level. Without a brief, you get a generic report that passes products you would reject.
Who to use
International firms (SGS, Bureau Veritas, Intertek, TÜV) cost more and have broad coverage; regional Chinese inspection companies (CCIC, CTI and specialised firms) offer the same man-day rate with inspectors closer to the clusters. Check that the inspector is independent of the factory and rotate inspectors on repeat orders.
Reading the report
Look beyond pass/fail: the defect photos tell you where the factory is weak, the measurement tables show drift from spec, and the packing check often finds the carton-marking errors that cause Amazon FBA rejections.