CBP Section 301 refunds hit $85 billion — what Canadian importers need to know about U.S. duty drawback and CBSA reassessment risk

Key Takeaways

• If your U.S. supplier claimed a CBP Section 301 exclusion that was later revoked, your CUSMA origin declaration may no longer hold under CBSA verification.
• CBSA accepts duty drawback claims within four years of the original CAD filing date, but revoked upstream exclusions can trigger reassessment plus interest.
• The CARM Client Portal now flags CAD amendments tied to U.S. refunds; importers must file corrected origin certificates within 90 days of knowledge of a change.
• Drawback mechanics differ between CBP and CBSA: a U.S. refund does not automatically grant relief on the Canadian side if you claimed preference on transaction value.

CBP certified $85 billion in Section 301 refunds — and Canadian importers who bought those goods are now fielding CBSA verification letters

As of late May 2025, U.S. Customs and Border Protection reported that its dedicated Section 301 exclusion portal has certified $85 billion in refund claims, with $20.6 billion already disbursed to importers and their suppliers. The program allows U.S. companies to recover duties paid on Chinese-origin goods that were later granted product-specific exclusions from the List 3 and List 4A tariffs.

For Canadian importers who source components or finished goods from U.S. suppliers, that sounds like good news upstream. The problem surfaces when you claimed CUSMA preference on your Canadian import and based your origin declaration on the supplier’s U.S. classification or an exclusion that CBP has now revoked or amended. CBSA does not automatically mirror CBP rulings, and a U.S. refund can unwind the origin math you relied on when you filed your Commercial Accounting Declaration last year.

We have been fielding CUSMA verification requests tied to this scenario since Q1 2025. The common thread: the Canadian importer certified origin using transaction value, the U.S. supplier’s CBP exclusion later expired or was withdrawn, and CBSA now wants proof that the goods still meet the regional value content or tariff-shift test under CUSMA Annex 4-B without that exclusion.

How CUSMA origin declarations interact with upstream U.S. tariff treatment

CUSMA preference is not a passthrough of U.S. tariff classification. When you file a CAD and claim preferential duty under CUSMA, you are certifying that the goods meet one of three origin criteria: wholly obtained in a CUSMA territory, produced entirely from originating materials, or satisfy the product-specific rule of origin in Annex 4-B (usually a tariff-shift or regional value content threshold).

Many importers rely on their U.S. supplier’s certificate of origin, which in turn references the supplier’s own import records and HS classification. If that supplier imported components from China under a Section 301 exclusion and later received a CBP refund because the exclusion was revoked, the bill of materials and valuation footnotes in the origin certificate may no longer add up. CBSA can ask you to re-demonstrate qualification using the supplier’s revised cost breakdown, and if you cannot, the preference claim fails.

The four-year audit window under section 42 of the Customs Act means CBSA can request verification long after release. We routinely see verification letters 18 to 24 months post-import, especially when CBSA cross-references CBP public exclusion lists and notices discrepancies in declared origin.

CARM-era CAD corrections and the 90-day disclosure rule

If you discover that your origin declaration was based on incorrect or outdated information, you must file a corrected CAD through the CARM Client Portal within 90 days of becoming aware of the error. The portal flags amendments tied to upstream refunds or exclusion changes, and the revised accounting triggers recalculation of duties owing, plus interest at the Bank of Canada rate plus 6 percent from the original release date.

Failure to correct within 90 days can elevate the matter to an AMPS contravention. A Level 3 infraction for incorrect origin starts around $2,500 for a first occurrence; Level 5 contraventions for knowingly false statements can reach $25,000 or higher and may be referred to the Public Prosecution Service of Canada.

The mechanics:

• Log into the CARM Client Portal and locate the original CAD transaction reference.
• Attach the corrected CUSMA origin certificate and any revised supplier documentation (bill of materials, cost worksheets, manufacturing affidavits).
• Pay the reassessed duties and interest within the payment period (usually 30 days for non-RPP accounts).
• If you hold a Release Prior to Payment bond, CBSA will debit your monthly K84 statement; ensure your financial security covers the new exposure.

We handle CAD amendments daily as part of our compliance practice, and the single biggest mistake importers make is waiting for CBSA to issue a verification letter instead of filing a voluntary correction as soon as they learn the upstream exclusion has changed.

Duty drawback in Canada versus CBP refunds: two separate regimes

Section 74 of the Customs Act allows Canadian importers to claim drawback of duties paid if goods are re-exported or destroyed under CBSA supervision, within four years of the original payment date. This is conceptually similar to CBP drawback but operates independently.

A U.S. supplier receiving a Section 301 refund does not trigger automatic relief in Canada. If you imported the goods into Canada, paid MFN duty (because you did not claim CUSMA preference), and later re-exported them, you may file a drawback claim. If you claimed CUSMA preference and paid zero duty, there is nothing to draw back.

The confusion arises when an importer claimed preference, CBSA later denies it during verification, and the importer pays the reassessed duty. At that point, if the goods have already been consumed or resold in Canada, drawback is not available. The only remedy is to appeal the verification decision to the Canada Border Services Agency Recourse Directorate or the Canadian International Trade Tribunal within 90 days of the reassessment notice.

What CBSA looks for during a CUSMA origin verification

CBSA may send the verification questionnaire to you, the exporter, or both. The request typically asks for:

• A detailed description of the production process and all materials used.
• HS 6-digit classification of each non-originating input.
• Proof that the finished good underwent the required tariff shift or meets the regional value content percentage.
• Purchase invoices, bills of lading, and commercial records spanning the 12 months prior to export.

If the U.S. exporter’s cost breakdown referenced a CBP exclusion that no longer exists, the non-originating material value may jump, pushing the regional value content below the CUSMA threshold (usually 60–75 percent depending on the product). CBSA will deny preference, apply MFN duty rates, and assess interest from the original CAD accounting date.

Under D11-4-16, the exporter has 30 days to respond. Extensions are granted if the exporter can demonstrate it needs time to compile manufacturing records, but silence or incomplete answers result in automatic denial.

Cross-border recordkeeping and the four-year retention rule

Both CBSA and CBP require importers and exporters to retain origin records for a minimum of five years (CBSA) or five years (CBP) from the date of import. In practice, Canadian importers should keep CUSMA certificates, supplier affidavits, and cost worksheets for at least five years to cover both CBSA post-release verification and any related CBP audit of the upstream U.S. import.

If your U.S. supplier undergoes a CBP audit and revises its origin position, you need to know immediately. We recommend quarterly reconciliation of CUSMA certificates against the supplier’s current CBP classifications and exclusion status, especially for high-volume automotive, electronics, and textile imports where Section 301 exclusions have been volatile.

When warehouse and inventory systems are involved, coordination between customs clearance and physical operations becomes critical. If a reassessment triggers a change in landed cost, your ERP and WMS lot-costing may need adjustment, and any goods still in a bonded or sufferance warehouse must be re-accounted before final release to the Canadian market.

Practical steps when your U.S. supplier receives a Section 301 refund

1. Request a copy of the CBP refund notice and the revised classification or exclusion determination.
2. Compare the supplier’s original CUSMA origin certificate to the new CBP position.
3. Re-run the regional value content calculation using the revised non-originating material values.
4. If the goods still qualify, document the analysis and keep it on file for the next CBSA verification.
5. If they do not qualify, file a corrected CAD within 90 days and pay the reassessed duty plus interest.
6. Update your supplier’s master origin profile in your trade compliance system to flag any CBP exclusion dependencies.

Ignoring the upstream change is not an option. CBSA cross-references public CBP exclusion lists, and the CARM Client Portal now surfaces discrepancies algorithmically during risk scoring. A reactive posture after CBSA issues a verification letter costs more in professional fees, interest, and potential penalties than a proactive amendment.

We track these notices for clients as part of our ongoing duty and trade advisory work, and the pattern is consistent: importers who disclose and correct early pay interest but avoid AMPS penalties, while those who wait for CBSA to find the issue face both.

If you claimed CUSMA preference on goods sourced from U.S. suppliers who have received or are pursuing Section 301 refunds, now is the time to audit your origin certificates and CAD filings. Get in touch and we will walk through your transaction history and supplier documentation before CBSA does.

Frequently Asked Questions

What is the deadline to file a duty drawback claim with CBSA?

Under section 74 of the Customs Act, importers have four years from the date duties were paid to file a drawback claim. The CARM Client Portal streamlines the submission, but you still need proof of re-export or destruction and the original CAD transaction reference.

If CBP refunds Section 301 duties on my U.S. supplier’s imports, does that change my CUSMA claim in Canada?

It can. If your CUSMA origin certificate referenced the supplier’s U.S. import classification or an exclusion that CBP later revoked, CBSA may request verification under CUSMA Chapter 6. You must demonstrate that the goods still qualify under the regional value content or tariff-shift rule, independent of the U.S. tariff treatment.

How long does CBSA give me to respond to a CUSMA origin verification request?

CBSA typically allows 30 days for the first response under D11-4-16, though extensions are granted if you can show the exporter needs time to compile records. If you miss the deadline, CBSA will deny the preference claim and reassess at MFN rates plus interest from the original release date.

What happens if I filed a CAD claiming CUSMA preference but later learn the origin declaration was wrong?

You must file a corrected Commercial Accounting Declaration through the CARM Client Portal within 90 days of discovering the error. The revised CAD triggers recalculation of duties owing, and you will pay interest at the prescribed Bank of Canada rate plus 6 percent from the original accounting date.

Can I claim duty drawback in Canada if I already received a CBP Section 301 refund in the U.S.?

Only if the goods were imported into Canada, duties paid, and then lawfully re-exported or destroyed. CBSA drawback under section 74 is independent of CBP refunds, but you cannot double-recover. If you claimed CUSMA preference and paid zero duty in Canada, there is nothing to draw back.

Does CBSA audit CUSMA origin certificates after the goods are released?

Yes. Post-release verifications can occur up to four years after the CAD accounting date. CBSA may send questionnaires to the exporter, request manufacturing records, or conduct a site visit. If the exporter fails to respond within the prescribed time, CBSA will deny preference and issue a reassessment.

What is the penalty for knowingly filing a false CUSMA origin declaration?

Under AMPS, a Level 5 contravention for false origin statements carries penalties starting at $25,000 and can reach six figures for repeat infractions. CBSA may also refer the case to the Public Prosecution Service of Canada if fraud is suspected.

Source: Supply Chain Dive