Section 301 probe of Vietnam: what Canadian importers need to watch

Key Takeaways

• U.S. Section 301 probes historically lead to tariff action; Canadian importers relying on Vietnam-sourced goods should model cost scenarios now.
• If U.S. tariffs tighten, expect production shifts to Mexico or China that will draw CBSA origin verification requests on CUSMA preference claims.
• Vietnam is already on CBSA’s watch list for textiles and furniture transshipment; a U.S. probe will intensify Canadian scrutiny of certificates of origin.
• CAD filings claiming MFN zero-duty treatment under CPTPP Chapter 2 must document substantial transformation if Vietnamese assembly uses Chinese inputs.

USTR opens Section 301 probe into Vietnam IP practices

The Office of the U.S. Trade Representative announced a Section 301 investigation into Vietnam’s intellectual property policies on May 12, 2025. The probe covers patent enforcement, trademark practices, and technology transfer requirements. Section 301 investigations typically run six to twelve months and often conclude with tariff action if USTR finds violations.

Canadian importers watching this should remember that U.S. trade policy moves tend to ripple north, not because CBSA mirrors U.S. tariffs, but because production shifts following U.S. tariff escalation create origin-verification pressure at the Canadian border.

If your supply chain relies on Vietnamese textiles, furniture, electronics assembly, or footwear, you need to model two scenarios: continued Vietnam sourcing under MFN or CPTPP duty treatment, and a supplier pivot to Mexico or China that triggers CUSMA or CPTPP origin verification sweeps.

Why this matters for Canadian CAD filings

Vietnam is already on CBSA’s radar for transshipment risk. We see routine origin-verification requests for goods classified under HS chapters 61-62 (apparel), 64 (footwear), and 94 (furniture) where Vietnamese assembly uses Chinese fabric, soles, or hardware. Those requests ask for bills of material, production flow charts, and supplier invoices to confirm substantial transformation under CPTPP Chapter 2 rules of origin.

If U.S. tariffs tighten on Vietnam, expect two immediate effects. Suppliers will shift production to alternative countries to preserve U.S. market access, and CBSA will intensify scrutiny of Canadian import declarations claiming preferential duty treatment from those same alternative countries.

Most importers filing a CAD through the CARM Client Portal assume MFN duty rates apply automatically and preference claims are optional. That’s true, but if your Vietnamese supplier qualifies for CPTPP zero-duty treatment and you’re paying the MFN rate, you’re overpaying. Conversely, if you claim CPTPP preference without validating substantial transformation, you’re exposed to AMPS penalties when CBSA audits the file.

CUSMA origin verification risk after supplier shifts

Section 301 tariff action historically pushes production to Mexico. Mexican assembly plants can often deliver comparable lead times and, if the goods qualify under CUSMA Annex 4-B product-specific rules, zero-duty entry into Canada.

The catch: CBSA has ramped up CUSMA origin verification since 2024, particularly on textile and automotive goods. If your Mexican supplier assembles garments using Chinese fabric or Vietnamese trim, the goods may fail the Chapter 4 yarn-forward rule. CBSA will request a certificate of origin, production records, and proof that the yarn originated in a CUSMA country (Canada, U.S., or Mexico).

We routinely file CADs claiming CUSMA preference for clients who moved production from Asia to Mexico in 2023-24. Half the time, CBSA sends a verification letter within 60 days. Most files clear with clean documentation, but delays cost two to four weeks and tie up release prior to payment security.

If your supplier is planning a Mexico shift in response to U.S. tariffs, confirm CUSMA eligibility before the first shipment. Fixing a failed preference claim after the fact means filing a voluntary correction within the 90-day window under Customs Act section 32.2, paying the MFN duty shortfall, and hoping CBSA waives the AMPS penalty.

CPTPP preference claims and Vietnamese substantial transformation

Canada and Vietnam are both CPTPP signatories. Goods wholly obtained or substantially transformed in Vietnam qualify for preferential duty treatment under CPTPP Chapter 2, provided the importer holds a valid certificate of origin and files the CAD with the correct preference indicator.

Substantial transformation is the sticking point. If your Vietnamese supplier assembles finished goods using Chinese components, CBSA will ask whether the assembly operation confers a new tariff classification at the HS 6-digit level and adds sufficient value. Vietnamese cut-and-sew of Chinese fabric usually qualifies (HS shift from 52-60 to 61-62). Vietnamese packaging of Chinese electronics usually does not (no HS shift, minimal value-add).

We see CBSA verification letters on CPTPP claims about as often as CUSMA requests. The difference: CPTPP audits tend to focus on apparel and furniture, while CUSMA audits skew toward automotive and steel. Both require the same level of documentation.

If you’re claiming CPTPP preference on Vietnamese imports, make sure your supplier can produce bills of material, production flow documentation, and proof of origin for inputs. CBSA gives you 30 days to respond to a verification letter. Missing that deadline means the preference claim is denied and you pay the MFN rate retroactively, plus interest.

SIMA exposure for Vietnamese steel and aluminum

CBSA enforces Special Import Measures Act (SIMA) duties on corrosion-resistant steel and certain aluminum extrusions from Vietnam. Normal-value margins range from 12% to 84% depending on the exporter, per the CBSA SIMA registry. If your supplier is on the registry and you file a CAD without declaring SIMA subject goods, you’re underpaying duties and exposed to an AMPS Level 2 or Level 3 penalty.

U.S. Section 301 action won’t directly change Canadian SIMA measures, but it often correlates with anti-dumping investigations. If USTR finds IP violations and imposes tariffs, the U.S. Commerce Department and ITC tend to open parallel AD/CVD cases. Canadian industry groups watch those filings and sometimes petition CBSA and the CITT to open mirror investigations.

If you import Vietnamese steel, aluminum, or any other product flagged under SIMA, check the registry before every CAD filing. SIMA margins update quarterly, and missing a rate change will cost you on the next CBSA audit.

What to do now

Map your Vietnamese import volume by HS classification. Confirm whether you’re claiming CPTPP preference or paying MFN rates. If you’re claiming preference, pull your certificates of origin and verify that your supplier’s production process meets substantial transformation rules.

If your supplier is considering a production shift to Mexico or China in response to potential U.S. tariffs, model the CUSMA or MFN duty impact before the move. Most importers assume Mexico equals zero duty under CUSMA, but that only holds if the goods meet Annex 4-B rules. Chinese re-sourcing means MFN duty plus potential SIMA exposure if the product category is already under investigation.

We handle origin verification responses and CUSMA / CPTPP qualification reviews daily. Section 301 investigations take months to resolve, but the supply-chain moves happen faster. If your Vietnamese supplier is planning a shift, validate the duty treatment and origin eligibility now, not after the first container clears.

Canadian importers relying on Vietnamese production should treat this probe as a planning trigger, not a wait-and-see headline. CAD filings under CARM Phase 2 require accurate preference claims and supporting documentation at the time of release. Fixing it later costs time, money, and AMPS penalty exposure. Run the numbers, confirm your certificates, and make sure your brokerage team has the origin documentation on file before CBSA asks.

If you’re modeling alternative sourcing or need a second look at your CPTPP or CUSMA claims, email us your HS classifications and supplier country list. We’ll tell you where the duty exposure sits and whether your origin documentation will survive a CBSA verification letter.

Frequently Asked Questions

What is a Section 301 investigation and why does it matter for Canadian importers?

Section 301 is a U.S. trade law mechanism that allows USTR to investigate foreign government practices and impose tariffs if violations are found. Canadian importers care because U.S. tariff action on Vietnam often triggers production shifts to alternative countries, which then shows up at the CBSA border as sudden origin-verification sweeps on CUSMA and CPTPP preference claims under the Customs Act.

Does Canada have its own investigation into Vietnam?

Not currently. Canada applies MFN duty rates to Vietnam and extends CPTPP preferential treatment under Chapter 2 since Vietnam acceded in 2018. CBSA has not published a formal verification campaign, but we routinely see file-specific certificate-of-origin requests for textiles (HS 61-62) and furniture (HS 94) where Vietnamese assembly relies on Chinese inputs.

Will my CAD filing be flagged if I import from Vietnam?

CBSA applies risk-based targeting. If you claim CPTPP zero-duty treatment and your Vietnamese supplier assembles using Chinese fabric or components, expect a CBSA verification letter requesting production records and bills of material within 30 days under CARM Phase 2 Release 3 procedures. Most flags resolve with clean documentation; delays happen when the origin certificate overstates local content.

What happens if U.S. tariffs on Vietnam push my supplier to shift production to Mexico?

You’ll need to confirm whether the Mexican plant qualifies for CUSMA origin under Annex 4-B product-specific rules. CBSA has tightened CUSMA verification since 2024, particularly on textile (Chapter 4 yarn-forward rule) and automotive (regional value content) claims. File the CAD with accurate CUSMA preference codes and keep the certificate of origin ready for audit.

Are Vietnamese goods subject to SIMA dumping duties in Canada?

Yes, on specific products. CBSA currently enforces SIMA measures on corrosion-resistant steel (NQ-2021-001) and certain aluminum extrusions (NQ-2009-004) from Vietnam, with normal-value margins between 12% and 84% depending on the exporter. Check the CBSA SIMA registry before filing a CAD to avoid underpayment penalties under AMPS.

How quickly can I correct a CAD if my Vietnamese origin claim is wrong?

You have a 90-day correction window under the Customs Act section 32.2 to file a voluntary adjustment through the CARM Client Portal. After 90 days, CBSA treats it as an audit finding and AMPS penalty exposure jumps to Level 2 or 3 depending on the shortfall. We file most origin corrections within two weeks once the supplier sends revised documentation.

Should I pre-emptively model alternative sourcing if U.S. tariffs hit Vietnam?

Yes. Map your HS 6-digit classifications, compare MFN versus CUSMA versus CPTPP duty treatment, and confirm whether your Mexican, Chinese, or Canadian alternative suppliers can deliver the same lead times and landed cost. Most importers wait until tariffs are announced; by then freight and factory slots are tight.

Source: Supply Chain Dive