Key Takeaways
- CBP's refund portal processed drawback claims in weeks; CBSA's CARM correction workflow routinely takes 90 days or longer.
- CAD amendments for duty overpayments require Form B2 and supporting documentation filed through the CARM Client Portal, not the old Customs Act s.74 paper route.
- If you posted an RPP bond and overpaid duties on the initial CAD, the overpayment sits on your K84 statement until CBSA processes the correction.
- Anticipating duty adjustments before you file the CAD is cheaper and faster than chasing refunds after release.
CBP moved fast. CBSA is not there yet.
U.S. Customs and Border Protection stood up a tariff refund portal in early 2025 and started returning funds to importers within weeks. The timeline surprised even CBP's own projections. Canadian importers watching that rollout have been asking the same question: when will CBSA's CARM system offer anything close?
The answer is not soon. CBSA's CARM Client Portal handles Commercial Accounting Declaration (CAD) filings and monthly financial reporting, but it does not yet include a dedicated duty-refund tracker or expedited correction queue. If you overpaid duties on a CAD filed in January, you are still looking at a 90-day minimum before the adjustment clears, and in practice we routinely see 120 days or longer in 2025.
That gap matters because the volume of duty corrections has climbed since CARM Phase 2 Release 3 went live. Importers who relied on brokers to file the old B3 form are now filing CADs themselves or working with new service providers, and classification errors, incorrect origin claims, and missed CUSMA preference declarations are showing up weeks after release. CBP's portal proved that a faster duty-adjustment workflow is technically possible. CBSA is not there yet.
The CARM correction workflow: Form B2 and the K84 lag
When you discover a duty overpayment after CBSA releases the goods, the correction route is Form B2 (Adjustment Request) submitted through the CARM Client Portal. The old Customs Act s.74 paper-based refund process still exists, but CBSA now directs most post-CARM corrections through the portal.
You submit the B2 with supporting documentation: commercial invoice, packing list, bill of lading, and any certificates of origin or lab reports that justify the adjustment. CBSA reviews the request, accepts or rejects it, and if accepted, issues the refund or applies the credit to your next K84 monthly statement.
If you used release prior to payment and posted an RPP bond, the overpaid amount sits on the K84 until CBSA processes the correction. The bond itself is not adjusted retroactively. That means your monthly financial security calculation reflects the higher duty amount until the refund posts, which can push your required bond balance higher than it should be for 90 to 120 days.
The Customs Act allows four years from the date of accounting to file a refund request, but most importers file within 90 days to keep the correction in the same fiscal quarter and avoid confusion in the annual audit. The four-year window is useful for SIMA cases where anti-dumping margins change after a tribunal review, or for HS classification rulings that apply retroactively, but for routine overpayments the sooner you file the B2, the sooner you close the loop.
Why anticipating the correction is cheaper than chasing it
CBP's refund portal moved quickly because the agency built the workflow with the assumption that tariff changes would generate thousands of correction requests. CBSA has not yet designed CARM around that assumption. The result is that proactive classification and origin review before you file the CAD is still the most reliable way to avoid the correction queue entirely.
We file CADs with HS 6-digit classification already vetted and CUSMA origin claims already documented. If the shipment qualifies for CETA preferential treatment, we confirm the certificate of origin before release, not after. If the goods are subject to SIMA and the supplier's country of origin triggers an anti-dumping margin, we flag that on the CAD so the correct duty posts from the start.
That front-end work costs less than filing a B2 correction three months later, waiting another 120 days for CBSA to process it, and carrying the overpaid amount on your K84 statement in the meantime. The correction workflow exists, and it works, but it is not fast and it is not automatic.
What Canadian importers should watch in 2025
CBSA has not announced plans to build a refund-tracking interface or to accelerate the B2 review queue. The agency's focus in 2025 remains stabilizing the core CARM Client Portal and resolving payment-posting issues that affected the first six months of mandatory adoption. Duty corrections are not the priority.
If you are filing CADs in-house, the single highest-value step you can take is to run the HS classification and origin determination before you submit the CAD, not after CBSA releases the shipment. If you are working with a broker, ask whether they review classification and duty calculation as part of the filing service or only after you request a correction. The difference is 90 days and a four-figure overpayment sitting on your books.
CBP's portal proved that faster refunds are possible when the system is designed around corrections as a normal workflow. CBSA is not there yet. Until the agency catches up, the best defence is not filing the correction at all.
CBSA verification and origin claims after the fact
One note of caution: if your B2 correction claims preferential duty treatment under CUSMA or CETA that you did not declare on the original CAD, CBSA may open a verification of origin. The agency has the authority under both agreements to request the original certification, contact the supplier, and in some cases audit the producer's records.
That process can take six to twelve months, and if CBSA denies the origin claim, you owe the full MFN duty plus interest calculated from the original release date. The correction is rejected, the overpayment becomes an underpayment, and you are looking at an AMPS contravention if the documentation was insufficient.
If you are filing a correction that changes the origin or classification, make sure the supporting evidence is complete before you submit the B2. CBSA is not required to give you a second chance to produce the certificate, and the verification clock does not stop while you chase the supplier for paperwork.
When to file and when to wait
Not every duty discrepancy is worth correcting. If the overpayment is less than CAD 100 and the administrative cost of preparing the B2, gathering the documentation, and tracking the refund exceeds the recovery, most importers let it go. If the overpayment is recurring across multiple shipments because of a systematic classification error or a missed origin claim, the correction is worth filing even if the individual amounts are small.
We track duty corrections by importer and by HS code. If the same classification issue appears on three consecutive CADs, we escalate it to compliance review and request an advance ruling from CBSA before the next shipment. That ruling binds the agency and eliminates the need for future corrections on the same product.
If the goods are stored at a bonded warehouse before you file the CAD, you have more time to confirm classification and origin before duties are posted. FENGYE's Montreal sufferance warehouse holds goods under CBSA control until you are ready to account, which gives you a window to resolve documentation issues without triggering a correction cycle.
What the CBP portal tells us about CARM's roadmap
CBP's refund portal succeeded because the agency treated it as a logistics problem, not a policy problem. The workflow assumed high volume, automated most of the review steps, and gave importers a tracking interface so they did not need to call the port every week for status updates.
CBSA has not yet adopted that model. The CARM Client Portal handles CAD submission and financial reporting, but it does not treat corrections as a first-class workflow. Until that changes, Canadian importers should plan for 90 to 120 days from B2 submission to refund, and should prioritize accuracy on the initial CAD over speed.
CBP proved that faster is possible. CBSA will get there. In the meantime, the correction queue is long, the process is manual, and the best strategy is not needing it.
If your last six months of CAD filings included duty adjustments you did not expect, that is the kind of pattern we review weekly. Get in touch.
Frequently Asked Questions
How long does CBSA take to process a duty refund request under CARM?
The Customs Act provides a 90-day correction window for most CAD amendments, but processing timelines at CBSA routinely stretch beyond 120 days in 2025. CBP's portal returned funds in weeks; CBSA's CARM correction queue is not yet at that pace.
What form do I file to correct an overpaid duty on a Commercial Accounting Declaration?
Use Form B2 (Adjustment Request) submitted through the CARM Client Portal. The old paper-based Customs Act s.74 refund process is no longer the primary route for post-CARM CAD corrections.
Can I claim a duty refund if I used release prior to payment?
Yes. If you posted an RPP bond and overpaid duties on the initial CAD, the overpayment appears on your K84 monthly statement and is refunded after CBSA accepts the B2 correction. The bond itself is not adjusted retroactively.
Does CBSA offer an online portal for tariff refunds like CBP does?
Not yet. CARM Phase 2 Release 3 introduced the Commercial Accounting Declaration workflow and client portal, but there is no dedicated refund-tracking interface equivalent to CBP's portal as of May 2025.
What is the deadline to file a CBSA duty adjustment after importing goods?
Under the Customs Act, you have four years from the date of accounting to request a refund or correction of duties paid, but most importers file within 90 days to keep the correction in the same fiscal quarter.
Will CBSA verify the origin certificate again if I file a CUSMA correction?
Possibly. CBSA may request the original CUSMA certification or launch a verification of origin if the correction claims preferential duty treatment that was not declared on the initial CAD. Keep the certificate and supplier affidavit ready.
Originally published at https://www.canflow-global.com/en/insights/cbsa-duty-refunds-under-carm-what-the-cbp-portal-tells-us-about-cad-corrections/.
