The presumption that goods qualifying for preferential tariff treatment under the United States–Mexico–Canada Agreement (USMCA or CUSMA) are immune from post‑entry duty assessments is not always borne out in practice. U.S. Customs and Border Protection (CBP) maintains robust authority to scrutinize entries, verify eligibility, and where documentation is incomplete or responsiveness is deficient assess duties notwithstanding an importer’s initial claim of exemption. This authority is frequently exercised through formal Requests for Information (RFIs), most notably by CBP Forms 28 and 29, which serve as the agency’s primary instruments for post‑entry verification and corrective action.
In recent years, the interplay between emergency tariff actions and preferential treatment frameworks has further highlighted the need for disciplined compliance. While certain executive actions have been amended to exempt USMCA‑qualifying products from additional ad valorem rates, the exemption applies only where eligibility is properly established and supported; RFIs are the procedural choke point through which CBP confirms or rejects an importer’s claim. The existence of an exemption in principle does not preclude duty liability in fact.
Moreover, CBP’s statutory and regulatory regime grants the agency access to information essential to assessing origin, classification, and valuation. When importers fail to provide requested records such as commercial invoices CBP may deny preferential treatment or reliquidate entries with duties assessed. The legal architecture, including 19 U.S.C. § 1520(d) and 19 C.F.R. Part 182, recognizes the agency’s discretion to seek additional documentation and to condition refunds or exemptions on adequate proof.
The compliance risk is therefore twofold: procedural and substantive. Procedurally, importers must respond timely and comprehensively to RFIs; substantively, they must maintain documentary substantiation of origin and other eligibility criteria. Failure at either level invites duty assessment, interest, and, potentially, penalties, even where the goods would otherwise qualify on paper for USMCA treatment
This article sets out a structured explanation of the RFIs’ mechanics, the legal basis for CBP’s information demands, the consequences of non‑compliance, and practical steps that importers can take to protect USMCA/CUSMA claims recognizing that exemption depends on proof and process rather than assertion alone.
CBP’s CF‑28 and CF‑29: Purpose, Process, and Practical Implications
CF‑28 Request for Information. CF‑28 is the formal vehicle CBP uses to obtain documents or clarifications necessary to verify the accuracy of an entry. This request often targets classification, valuation, country of origin, or the basis for preferential treatment under USMCA. It is typically issued post‑import but prior to final liquidation, and the standard response window is 30 days from issuance shorter deadlines may apply depending on circumstances.
The CF‑28 is not, by itself, a notice of investigation; however, it is a serious compliance event. If CBP receives no response, an incomplete response, or a response that fails to address the agency’s concerns, the outcome may include duty assessment, rejection of preferential claims, or application of additional tariffs such as those associated with certain trade actions. The operational rule is simple: timely, thorough engagement is essential.
CF‑29 Notice of Action. CF‑29 communicates CBP’s determination after review of the information provided. It may announce changes to classification or valuation, denial of USMCA treatment, or other corrective actions impacting duty liability. The CF‑29 reflects CBP’s evaluation of the evidentiary record; if the record does not substantiate USMCA eligibility, duties can be assessed even if the importer claimed exemption at entry.
Taken together, CF‑28 and CF‑29 form a procedural continuum. The first seeks data; the second implements a decision. Importers should anticipate that RFIs will request core documentation commercial invoices, bills of materials, supplier declarations, and origin certifications and should be prepared to produce them in full and on time.
A disciplined approach to these notices reduces risk. Establish internal workflows to capture, index, and retrieve records; train relevant personnel to recognize RFI triggers; and coordinate responses across customs brokers, suppliers, and trade counsel. RFIs are neither rare nor exceptional they are routine instruments through which CBP enforces the integrity of the USMCA regime.
Why RFIs Matter Even When Goods Are USMCA/CUSMA‑Eligible
USMCA eligibility hinges on origin rules and documentation, not merely on a certificate’s existence. CBP may test the claim by requesting supplementary proofs; where gaps appear, eligibility can be denied. A recent ruling affirmed CBP’s authority to require commercial invoices in support of a post‑importation USMCA claim, underscoring that certificates alone may be insufficient.
RFIs also mediate the relationship between emergency tariff actions and exemptions. When executive guidance clarifies that USMCA‑qualifying goods are exempt from additional border‑related duties, those exemptions still presuppose a valid claim. In practice, CBP uses RFIs to confirm whether goods truly qualify before allowing the exemption to attach.
From a legal perspective, RFIs reflect CBP’s statutory mandate to collect the information it deems essential to assess claims. The governing framework 19 U.S.C. § 1520(d) and 19 C.F.R. §§ 182.31–182.33 provides the mechanisms for post‑importation refunds and the conditions under which CBP will reliquidate entries. RFIs allow CBP to evaluate compliance with these conditions.
Operationally, RFIs highlight vulnerabilities in supply chain documentation. If suppliers fail to provide detailed origin breakdowns or if costed bills of materials are incomplete, the importer may be unable to substantiate preferential status. RFIs, therefore, expose and penalize weak recordkeeping: the result can be denial of USMCA claims and assessment of duties otherwise avoidable.
Finally, RFIs matter because liquidation timelines are unforgiving. Once entries liquidate, options narrow; but prior to liquidation, RFIs can reshape outcomes. A robust, timely response can preserve eligibility and avoid duty assessments; conversely, a deficient response can lead to unwelcome CF‑29 actions and financial consequences.
The Consequences of Non‑Compliance: Duties, Interest, and More
The immediate consequence of ignoring or inadequately answering an RFI is the denial of preferential tariff treatment. CBP may assess the standard duty rate applicable to the Harmonized Tariff Schedule (HTSUS) classification of the goods, and depending on contemporaneous trade actions may also apply additional ad valorem rates introduced by executive orders or implementing guidance.
Duty assessments may be retroactive via reliquidation, meaning that entries initially cleared with USMCA claims can later carry duties once CBP determines the claim lacked substantiation. This imposes immediate cash costs and complicates financial reporting, particularly where companies have recognized savings predicated on USMCA eligibility.
Non‑compliance can also trigger interest accrual and penalties. While specific penalty exposure depends on the facts (e.g., negligence vs. gross negligence), CBP’s corrective mechanisms are designed to deter weak compliance practices. The agency expects importers to maintain and produce records that substantiate claims; RFIs are the means by which this expectation is enforced.
In some regimes, additional duties connected to emergency tariff actions may be non‑drawbackable, limiting offset strategies and magnifying net cost. Guidance issued in connection with recent border‑related tariffs emphasized that the additional duties stack atop baseline HTSUS rates and may not be eligible for duty drawback, thereby heightening the risk of permanent cost increases when claims fail.
Beyond direct monetary effects, RFI mismanagement can damage supplier relationships and internal stakeholder confidence. When CBP denies a claim due to missing supplier documents, the importer bears the duty burden but may have limited recourse to recover costs upstream. This underscores the necessity of contractual and operational controls ensuring suppliers furnish the data needed for USMCA substantiation.
CBP’s Legal Authority to Demand Documentation Beyond the Certificate
Importers sometimes assume that a valid USMCA certificate alone suffices to secure preferential treatment. CBP practice and precedent refute this assumption. Headquarters has affirmed that, in the context of 19 U.S.C. § 1520(d), CBP may request “additional documentation” it considers essential to evaluate claims, including commercial invoices even if specific regulations seem silent on that point.
The regulatory framework for post‑importation duty refunds under USMCA is set out in 19 C.F.R. Subpart D (Part 182). These provisions detail the content and processing of claims, including the requirement to provide certifications and statements. Importantly, CBP’s processing authority includes verifying whether entries have been liquidated and whether claims meet the documentary standards. RFIs are a procedural extension of this authority.
Furthermore, entry requirements under 19 C.F.R. § 142.3(a)(3) obligate importers to provide copies of commercial invoices as part of the entry package. Headquarters reasoned that, because invoices are required at entry, requesting them in a post‑entry USMCA audit is both lawful and logical. Refusing to supply invoices invites denial of preferential treatment and affirmation of protest denials.
CBP’s operational guidance and industry advisories consistently warn that RFIs will be used to verify preferential treatment claims. Practical bulletins from trade practitioners emphasize that incomplete responses can lead to assessment of additional duties including those arising under separate tariff actions illustrating how legal authority translates into tangible cost exposure. The certificate of origin is necessary but not sufficient. CBP’s authority extends to all documents material to origin, classification, and valuation, and the agency will exercise that authority through RFIs. Importers must be prepared to furnish a comprehensive evidentiary record to sustain their claims.
Practical Safeguards: How to Protect USMCA/CUSMA Claims Against RFI Risk
Document discipline. Maintain complete commercial invoices, costed bills of materials, supplier origin declarations, manufacturing process descriptions, and the USMCA certification. Index these records to entry numbers and HTSUS classifications to enable rapid retrieval when RFIs arrive. CBP expects documentary rigor; discipline minimizes the risk of denial.
Response readiness. Establish internal standard operating procedures (SOPs) for CF‑28 and CF‑29 handling: define roles, timelines, and escalation paths; pre‑assign responsibility for gathering supplier documents; and rehearse responses. The typical 30‑day window is tight; preparedness ensures timely, comprehensive submissions.
Supplier governance. Incorporate contractual obligations requiring timely provision of origin and cost documents. Consider audit rights and corrective action clauses. Denied claims frequently trace to supplier documentation gaps; governance closes those gaps and shifts responsibility appropriately.
Professional support. When RFIs are complex or when CBP signals concerns about origin methodology or valuation reach out to external experts that can help align responses with statutory and regulatory requirements and can assist with protests or post‑entry claims under 19 C.F.R. §§ 182.31–182.33 when appropriate.
Monitor tariff developments. Track CBP Cargo Systems Messaging Service (CSMS) and carrier/regulatory advisories to understand the interaction between emergency tariffs and USMCA exemptions. Exemption applies only if goods qualify; RFIs are the mechanism for verification. Awareness ensures you anticipate documentation demands aligned to current policy.
Misclassification Under the Harmonized Tariff Schedule (HTSUS): Process and Penalties
Detection and initial CBP action. When CBP suspects that goods have been entered under an incorrect HTSUS code, it typically initiates post‑entry scrutiny through a CF‑28 (Request for Information) and, if concerns persist, a CF‑29 (Notice of Action) to change classification, adjust duty rates, and advance the rate of duty on the affected entries. These notices are routine instruments used to verify classification accuracy and can result in reassessment of duties even refunds, where the correct classification yields a lower rate followed by instructions on how future entries should be declared. Timely, complete responses are essential; ineffectual replies commonly lead to rate advances and additional duty assessments.
Corrective pathways: PSC and Protest. If you discover a misclassification before liquidation, the principal corrective mechanism is a Post Summary Correction (PSC) filed in ACE within the earlier of 300 days from entry or 15 days before scheduled liquidation; PSCs are the sole electronic method to correct entry summaries prior to liquidation and require payment of any resulting amounts due. Once liquidation has occurred, classification disputes must be challenged via a protest under 19 U.S.C. § 1514, generally within 180 days of liquidation, with ACE providing an electronic protest module and CBP Centers able to extend liquidation in limited circumstances.
Civil penalty framework (19 U.S.C. § 1592). Beyond duty corrections, misclassification can trigger civil penalties under 19 U.S.C. § 1592 for negligence, gross negligence, or fraud, even if the government suffers no revenue loss. CBP’s penalty guidelines (Appendix B to 19 CFR Part 171) and enforcement practice recognize maximum non‑revenue penalty tiers of up to 20% of the dutiable value for negligence, 40% for gross negligence, and up to the domestic value of the merchandise for fraud, with pre‑penalty and penalty notices outlining alleged violations and proposed penalty amounts.
Mitigation via prior disclosure. If a misclassification is self‑identified, a Prior Disclosure under 19 CFR § 162.74 made before knowledge of a formal investigation can substantially mitigate penalties (often to interest on the loss of duties for negligent/grossly negligent cases and capped amounts for fraud), provided the disclosing party tenders any actual duty loss and supplies the required detail. Practitioners caution that in some instances CBP may treat a CF‑28 or CF‑29 as evidence of an investigation’s commencement, potentially limiting eligibility for prior disclosure; therefore, timing and counsel engagement are critical when evaluating this option.
Broader exposure: trade remedies and special duties. Misclassification can cascade into trade remedy liabilities (e.g., Section 301/232) and AD/CVD exposure if the correct classification renders the goods subject to additional measures; CBP frequently uses CF‑28/CF‑29 workflows to scrutinize such issues, and EAPA investigations may follow where AD/CVD evasion is suspected, with duty liabilities that can be significant. Consequently, classification governance should be integrated with continuous monitoring of tariff actions and origin/valuation controls to prevent compound duty exposure.
Conclusion
Preferential tariff treatment under USMCA/CUSMA is contingent upon demonstrable compliance, not mere assertion. CBP’s RFIs implemented through CF‑28 and CF‑29 operate as the principal verification tools by which the agency tests origin, classification, and valuation claims and, as necessary, assesses duties when claims lack substantiation. The availability of exemptions under evolving tariff actions strengthens, rather than weakens, the case for rigorous documentation: exemptions attach only to verified eligibility.
Legal authority under 19 U.S.C. § 1520(d) and 19 C.F.R. Part 182 permits CBP to demand additional documentation beyond the certificate of origin, including commercial invoices and other records foundational to origin analysis. Refusal or failure to provide these documents can result in denial of preferential treatment, retroactive duty assessments via reliquidation, interest, and penalties.
Accordingly, importers should treat RFIs as critical compliance events. Comprehensive recordkeeping, prompt and thorough responses, supplier governance, and professional support are essential safeguards against duty exposure. These measures transform USMCA claims from aspirational to defensible, ensuring that preferential treatment survives the scrutiny RFIs are designed to apply.
Even USMCA‑eligible products can incur duties when RFIs reveal deficiencies. The antidote is disciplined compliance: prepare, document, respond, and verify. In doing so, importers convert policy advantages into realized savings, resilient against the routine but consequential oversight CBP performs.