What CBP Actually Checks When They Audit Your China Supplier
Updated February 2026 | CBP enforcement priorities
A client was importing performance gloves into the U.S. Two color variants. Same supplier. Same tech pack. Selling well.
Then CBP flagged the shipment.
Not because of tariffs. Not because of Xinjiang. Because something didn't match.
We ran independent lab testing. AATCC 20A fiber content analysis. CPSC-accepted lab.
Here's what we found:
First variant: Polyester/cotton/spandex blend.
Second variant: Nylon/spandex blend.
Same brand. Same SKU. Same supplier story. Two completely different fiber compositions.
From CBP's perspective, this isn't a small mistake. It's four separate compliance risks under one shipment:
- Wrong HTS classification - Fiber content drives classification logic. Synthetic vs. natural fiber changes duty rates and trade agreement eligibility.
- Wrong duty calculation - Synthetic gloves carry high base duty. China adds Section 301 tariffs on top. Getting fiber content wrong can double your landed cost.
- Country of origin risk - When products don't match specs, CBP suspects factory substitution or transshipment. They assume you don't know who's really making your goods.
- False marketing claims - Product descriptions that don't match actual fiber content trigger consumer protection flags and Customs enforcement.
This is exactly the inconsistency that escalates into a CF-28 request, then a CF-29, then a full supplier audit.
And the client had no idea until we tested the gloves ourselves.
What We Did
We solved it the way CBP expects importers to solve it: with proof, not supplier assurances.
1. Independent lab testing
We ordered fiber content analysis from a CPSC-accepted lab. Clean, defensible numbers. No relying on factory COAs or "trust me" documents.
2. Rebuilt the compliance story around facts
Instead of letting the supplier control the narrative, we built the importer's position on:
- Actual fiber composition
- Material differences between SKUs
- Component analysis per variant
That gave CBP a clear technical basis for classification and risk review.
3. Isolated the root cause
The two glove types were clearly coming from different production lines, different factories, or undisclosed subcontracting.
We treated it as a substitution risk, not a "quality variance."
4. Created an audit-ready compliance packet
We packaged the evidence into the format CBP expects in a reasonable care file:
- Lab report
- Classification memo
- COO determination under textile rules
- Discrepancy explanation
- Supplier escalation actions taken
So if CBP asks again, the importer has documentation that shows they took action.
5. Forced supplier accountability
We demanded BOM documentation and knitting specs from the Guangdong factory. Made it clear:
- No documentation = no future shipments
- No consistency = supplier removed
The Result
The client went from a weak position ("the factory said it's fine") to a strong position:
- Independent proof of fiber content
- Clear classification and duty logic
- COO risk addressed with supplier accountability
- Clean reasonable care narrative
- Supplier on notice
That's what protects an importer under 2025-2026 CBP enforcement.
What CBP Actually Checks
When CBP audits your China supplier - whether through a CF-28, site visit, or focused assessment - they're not checking if your factory is "good."
They're checking if you know what you're importing.
They look for:
Fiber content vs. classification - Does the actual material match the HTS code you declared? Synthetic vs. natural fiber. Blends vs. single-material. Weight per square meter for textiles.
Component sourcing vs. country of origin - Where do the materials come from? If you're claiming "Made in Vietnam" but all inputs are Chinese, CBP will reclassify your goods as Chinese origin and retroactively assess Section 301 tariffs.
Production consistency vs. supplier claims - Are you getting the same product every shipment, or is the factory substituting materials, subcontracting without disclosure, or running multiple production lines under one PO?
Marketing claims vs. actual product - Product descriptions that don't match actual materials. Origin claims that don't match production reality. CBP coordinates with FTC on deceptive claims.
Supplier transparency vs. reasonable care - Can you prove who made your goods, with what materials, at which facility? Or are you relying on a trading company's word?
If you can't answer these questions with documentation, CBP assumes you're either negligent or complicit.
Why Supplier Audits Don't Catch This
Most factory audits check:
- Business licenses
- Labor conditions
- Fire safety
- Social compliance certifications
None of that tells you if the product leaving the factory matches the product on your tech pack.
CBP doesn't care if your Shenzhen supplier has ISO 9001. They care if you can prove what's in the box matches what you declared at the port.
That requires:
- Independent material testing
- Production flow verification
- Component traceability
- Supplier contract enforcement
Most importers don't do this until CBP forces them to. By then, you're defending a CF-28 with no documentation and a supplier who's stopped returning emails.
What This Means for You
If you're importing from China, Vietnam, India, or Indonesia in 2025-2026, here's what CBP expects:
You own reasonable care. Your customs broker can't fix what your supplier broke. Your freight forwarder isn't responsible for fiber content. Compliance starts at the factory, not the port.
Supplier assurances are not documentation. "Factory said it's fine" is not a compliance strategy. CBP wants independent verification, material testing, and production records.
Inconsistency triggers audits. One shipment with the wrong fiber content. One COO discrepancy. One Xinjiang-linked input. That's all it takes to escalate into a full focused assessment.
Moving production doesn't move compliance risk. China+1 doesn't solve this. If your Hanoi factory is using Chinese yarn, Chinese hardware, or Chinese subcontractors, you still have exposure.
The importers who survive CBP enforcement are the ones who verify their suppliers before CBP does.
Frequently Asked Questions
Q: What does CBP check during a supplier audit in China?
CBP verifies fiber content vs. HTS classification, component sourcing for country of origin, production consistency, and supplier transparency. They want proof you know what you're importing - not just what the factory claims.
Q: How long does a supplier verification take?
On-site verification in China or Vietnam takes 1-2 days depending on product complexity. Lab testing adds 5-7 days. Full compliance packet delivered within 2 weeks.
Q: What documents does CBP require for reasonable care?
Independent lab reports, production records, BOM documentation, supplier contracts, and country of origin determinations. "Factory said it's fine" doesn't count as reasonable care.
Q: Can my customs broker handle supplier compliance?
No. Your broker files paperwork at the port. Compliance starts at the factory - material sourcing, production flow, component traceability. That requires boots on the ground in Asia.
Need supplier verification in China or Vietnam?
We do on-site audits that check what CBP will check: material sourcing, production flow, component traceability, and export readiness. No inspection, no load. No customs readiness, no ETD.
