How we verify suppliers

The problem we solve

Generic B2B platforms (Alibaba, Made-in-China, Global Sources) list hundreds of "suppliers" per product category, the majority of whom are trading companies — sales offices that don't manufacture anything but resell from various factories. Buyers can't tell which listings are real factories and which are middlemen, so they end up paying trading-company markups and getting inconsistent product.

PartzealHQ filters this by verifying every supplier through a multi-step process. We list fewer suppliers per part than Alibaba — but every one is a real manufacturer.

Step 1 — Documentation review

For every supplier candidate we collect:

• Business license (营业执照) — verified against China's national enterprise registration database
• Quality certifications — IATF 16949 and/or ISO 9001 with issuing body and certificate number
• Export records sample — recent customs declarations or shipping documents showing real export activity
• Factory photos — exterior, production floor, QC area, warehouse
• Product line documentation — what they make, capacity per SKU family, key customers (anonymized if needed)

Documents that don't match each other (e.g., business license shows a different company name than the IATF certificate) are an immediate disqualification — no further review.

Step 2 — Certificate verification

IATF 16949 and ISO 9001 certificates are issued by accredited bodies (TÜV Süd, SGS, BV, DEKRA, DNV, and others) that maintain public online databases of valid certificates. We verify every claimed certificate against the issuing body's database — checking certificate number, scope, validity dates, and that the certified company name matches the supplier we're evaluating.

Forged or expired certificates are common in Chinese B2B. Around 15-20% of supplier candidates we evaluate have certification documentation that fails this verification step. They don't get listed.

Step 3 — Address verification (satellite)

Real auto-parts factories operate in industrial zones (开发区 / 工业园) with specific layout signatures: parking lots full of motorbikes and trucks, large building footprints (typically 3,000+ m²), visible loading docks, and material storage yards. Trading companies pretending to be factories typically list addresses in commercial buildings or have addresses that, on satellite imagery, show no industrial activity.

We use Google Earth and Baidu Maps satellite imagery to verify each stated factory address shows a real industrial facility consistent with the supplier's claimed scale. Addresses that don't match the claim are flagged for follow-up; persistent inconsistencies result in disqualification.

Step 4 — Customer reference checks

We ask each supplier for at least one customer reference — ideally an export customer, ideally with a 2+ year relationship. We then contact the reference and confirm: the supplier-customer relationship exists and has been productive, the product quality has been consistent, payment terms have been honored, and any past issues were resolved professionally.

We do not publish the reference customer's name or contact info — references are provided for our internal verification only. Suppliers who can't or won't provide references are not listed.

Step 5 — Video walkthrough or on-site visit

For each verified supplier, either:

• Video walkthrough: a 15-30 minute video tour of the production facility that we record over a video call with the supplier's plant manager. Real-time, unedited. We see the actual production line, not a curated showroom.
• On-site visit: for our Premium-tier suppliers and for major Tier-1 candidates, we visit the factory in person. 4-6 hours minimum, with technical questions covering the full process flow.

The video walkthrough is a hard requirement. Suppliers who refuse video tours or offer only pre-recorded marketing footage are not listed.

Tier classification

After verification, suppliers are classified into one of two tiers:

• ✓ Verified — passed all 5 steps. Listed in our directory and matched to relevant OEM pages. The vast majority of our suppliers.
• ⭐ Premium — Verified + on-site visit completed, IATF 16949 certified, established export relationships with Tier-1 aftermarket distributors, and demonstrated capacity in the Toyota Camry SKU range. Premium suppliers get priority placement and additional buyer-inquiry routing.

What verification is NOT

Important honest disclaimers:

• Verification is not a quality guarantee. Even verified factories can produce defective batches. Buyers should always sample-test before production volume orders and consider third-party pre-shipment inspection (SGS, BV, Intertek) for orders over $20K.
• Verification is point-in-time. We re-verify certifications annually and check that suppliers are still operating, but we don't continuously monitor their day-to-day production quality.
• Verification doesn't guarantee any specific commercial outcome. Suppliers may refuse to quote if your volume is too small, prices may not match your target, lead times may not meet your deadlines. We verify capability; commercial fit is between buyer and supplier.

If you have a complaint

If you've worked with a PartzealHQ-listed supplier and the relationship has gone wrong — quality issues, payment disputes, supplier non-responsiveness — please email trust@partzeal.com. We investigate every complaint and adjust supplier listings (or remove them) based on credible evidence. Our verification process is only as good as our follow-up.