Unclaimed CUSMA, CETA and CPTPP preference on past Canadian entries: the refund window, the proof and what it leaves behind

Why do agreement rates go unclaimed on Canadian entries?

Canada has trade agreements with the US and Mexico, the EU, the UK, the CPTPP countries and the other partners listed below, and on many tariff items the agreement rate is free while the Most-Favoured-Nation rate is not. Leather footwear under tariff item 6403.99.99 carries 18% MFN and nothing under CUSMA, CETA, CPTPP or the Canada-UK agreement; cotton T-shirts under 6109.10.00 are the same (Customs Tariff 2026, Chapters 61 and 64). Every shipment entered at MFN instead is an overpayment of the full rate.

The reasons are mundane and repeat across a year of entries:

• The proof of origin was not on file when the CAD was filed, so the broker used MFN rather than claim without it.
• The supplier's product qualifies, but nobody asked the supplier.
• The broker's product file defaults to MFN for a part number and was never updated.
• A new supplier in a CPTPP or CETA country replaced a non-agreement supplier, and the tariff treatment on the product file did not change.

Canadian law allows the claim to be made after the fact, for four years. That is longer than the window many importers assume, because the old NAFTA rule was one year and some CBSA pages still describe it.

Which tariff treatment code was on the line?

The tariff treatment code on each CAD line says which rate column the importer claimed. Memorandum D17-1-10, Appendix H, lists them. The ones that matter for this audit:

The memorandum also lists codes for Costa Rica, the EFTA states, Peru, Colombia, Jordan, Panama, Honduras and Ukraine. Using an agreement code is a declaration that the goods originate and, for CUSMA, CCFTA and CCRFTA, that the importer holds a valid certificate of origin; D17-1-10 warns that deliberate use of those codes on goods not entitled to them "may result in enforcement action".

The audit query is simple: every line coded 002 or 009 whose country of origin appears in an agreement and whose tariff item has a lower rate under that agreement on the release date. Those lines are the refund candidates. Check the country against the CBSA's list of countries and tariff treatments: it shows, for example, that Vietnam is entitled to the CPTPP tariff but not the General Preferential Tariff, so a Vietnamese line at MFN may be a CPTPP refund and cannot be a GPT one.

How long do you have, agreement by agreement?

Two paragraphs of section 74 of the Customs Act cover goods that were eligible for a preference that was not claimed at accounting.

• Paragraph 74(1)(c.11) covers goods "imported from Israel or another CIFTA beneficiary or from a country or territory set out in column 1 of Part 4 of the schedule". Subparagraph 74(3)(b)(i) gives four years after the goods were accounted for.
• Paragraph 74(1)(c.1) covers goods exported from Chile, with one year after accounting "or such longer period as may be prescribed". Memorandum D6-2-3 says that for CCFTA goods imported on or after March 1, 2014, the refund request must be made within four years.

Part 4 of the schedule to the Customs Act, as consolidated to October 19, 2026:

The CBSA's CUSMA guidance confirms that when CUSMA came into force the one-year NAFTA window was extended "to provide importers with a period of four years from the date the goods were accounted for". Memorandum D6-2-3, dated 2018, still describes the one-year NAFTA rule; the Act and the CUSMA guidance govern.

Four years is counted from accounting, line by line. A CAD accounted for in June 2023 stays claimable until June 2027; one from August 2022 is already out.

What proof of origin does each agreement require?

A refund request for an unclaimed preference has to include the proof the agreement requires. D6-2-3 says plainly: "All refund requests must include the relevant Certificate of Origin." Memorandum D11-4-2 describes each form.

Three details catch claims out.

1. Low-value shipments need no proof. D11-4-2 says that for commercial goods imported on or after July 1, 2020 with an estimated value for duty not exceeding CAD 3,300, "a proof of origin is not required" under any agreement in force. The CBSA may ask for a certificate if a shipment is one of a series split to stay under the threshold. D6-2-3 still prints older thresholds; D11-4-2 and the CUSMA guidance give CAD 3,300.
2. A CETA declaration can cover a period. The origin declaration may cover multiple shipments of identical products for up to 12 months, and every importation must fall inside the period stated.
3. A third-country invoice changes the form. D11-4-2 notes that under CPTPP and CUSMA, if the invoice is issued in a non-party, the certification of origin must be separate from the invoice.

Proof is not the same as origin. The certification says the goods meet the rule of origin; if they do not, the refund will be denied as ineligible. And where a preference was claimed on an original CAD for goods that do not qualify, that line is an underpayment to correct under section 32.2, not a refund.

What does a preference not remove?

A trade-agreement rate replaces the customs duty rate on the line. Everything else stays.

• Surtaxes on US goods. The United States Surtax Order (2026) applies to goods "eligible to be marked as goods of the United States", tested under the marking rules, not the CUSMA preference rules. Customs Notice 26-23 says the surtax is payable "in addition to any other duties owing", and its worked examples charge it on goods with a 0% duty rate.
• The steel derivative surtax on agreement goods. The Steel Derivative Goods Surtax Order excludes goods originating in Canada and goods caught by certain other surtax orders. It does not exclude goods from CETA, CPTPP or CUSMA countries.
• The steel quota surtax. The quota order excludes Canada, the US and Mexico, but its Schedule 3, "List of Countries with Trade Agreement", puts the EU countries, Japan, Korea, Chile and other partners under their own quotas; over the quota or without a permit, those goods pay the 50% surtax whatever the tariff treatment.
• SIMA duties. Anti-dumping and countervailing duties depend on the goods, the country and the exporter, not on the tariff treatment.
• GST. GST is charged on the value for tax, which adds duties and surtax to the value for duty. A refund of duty lowers the GST base. Memorandum D17-2-1 says the CBSA does not credit overpaid GST to the importer's account: GST registrants receive it as an input tax credit from the Canada Revenue Agency, and non-registrants apply to the CRA on Form GST189.

Surtax and SIMA relief come through other routes: surtax remission or drawback (duties relief and drawback on past Canadian entries) and a SIMA re-determination. Which surtax a line should carry is covered in why your CAD shows the wrong surtax.

A worked set of lines

The figures are illustrative and round. Three lines of a broker accounting export, all entered at MFN, tariff treatment 002, and all for goods that the supplier confirms meet the agreement's rule of origin. Rates are from the Customs Tariff 2026.

Line 1 is claimable under paragraph 74(1)(c.11) until June 2027, with a CETA origin declaration from the Italian exporter. Refund: CAD 14,400.

Line 2 is claimable until March 2029 with a CPTPP certification of origin. Vietnam has no General Preferential Tariff entitlement, so CPTPP is the only route. Refund: CAD 14,400.

Line 3 is where importers expect too much. The CUSMA claim returns the CAD 9,000 of customs duty. The CAD 25,000 surtax stays, because the T-shirts are US goods under the marking rules and tariff item 6109.10.00 is on Schedule 3 of the 2026 order. The GST changes with the duty only:

The GST difference of CAD 450 is recovered as an input tax credit, not through the CBSA refund. The surtax may still qualify for remission, which is a separate claim.

Across the three lines, CAD 37,800 of customs duty comes back.

How do you file the refund?

In CARM, an unclaimed preference is a refund adjustment of the CAD, filed by the importer or an authorized representative, with the proof of origin uploaded as supporting documentation. The filing steps, reason codes and interest are in correcting a Canadian entry. Two features of section 74 are specific to preference claims:

• A grant counts as a re-determination. Subsection 74(1.1) treats a refund under paragraph (c.1) or (c.11) as a re-determination of origin, so the CBSA's decision is the starting point for any later dispute.
• Why a denial matters. Under subsection 74(4), a denial because the goods were not eligible for the preference is treated as a re-determination and can be disputed under section 60. Under subsection 74(5), a denial for incomplete or inaccurate documents is not, so fix the documents and refile while the four years are still running.

Do not mix directions in one filing. If the same audit finds lines that claimed a preference without valid proof, those are underpayments with a 90-day correction duty under section 32.2, filed separately.

How does this differ from a US claim?

An importer claiming on both sides of the border should not apply one country's window to the other. In Canada, an unclaimed CUSMA preference is a section 74 refund with four years from accounting, and the same four years apply to CETA, CPTPP and the other Part 4 agreements. The US has its own post-importation claim procedure and time limits for USMCA and for its other agreements; see unclaimed USMCA preference on past entries and FTA preference claims on past entries.

How do you find the lines in your own entries?

1. Pull four years of CAD and B3 lines from the broker accounting export, with tariff item, origin, tariff treatment code, value for duty, duty, surtax and accounting date.
2. Flag every MFN or GPT line from an agreement country where the agreement rate on the release date is lower. You can check the rates for any tariff item, origin and date in the duty calculator.
3. Rank by duty at stake and by deadline. Lines accounted for more than three and a half years ago go first.
4. Group by supplier and part number and ask each supplier for a certification or origin declaration covering the goods and period.
5. Separate low-value shipments of CAD 3,300 or less, which need no proof.
6. File refund adjustments with the proof attached; keep the surtax, SIMA and GST expectations realistic.
7. Fix the product file so the next shipment is entered at the agreement rate with the proof on file.

TariffSense reads CAD/B3 lines and broker accounting exports, checks every line's tariff treatment against the origin and the agreement rates in force on its release date, and flags MFN lines that an agreement would have made cheaper, with the duty at stake and the last day to claim, alongside the surtax and SIMA that would remain. Filing stays with your broker or your own CARM account. The post-entry audit page shows what goes in and what comes back.

What should you do next on your own entries?

Sort the last four years of entries by tariff treatment code and origin, and list the MFN lines from CUSMA, CETA, CPTPP and UK suppliers on tariff items with a free agreement rate. Start with the oldest, because the window closes line by line. Confirm eligibility and the filing route with a licensed customs broker or trade counsel before you file.