Ten digits, three blocks, two different authorities. Only one of those blocks carries the rate.
The Canadian classification number reads in three blocks that share neither origin nor function. The first six digits come from the HS Convention and are common to every party. Digits 7 and 8 form the Canadian tariff subheading: that is what carries the rates, one per tariff treatment. Digits 9 and 10 make up the statistical suffix, which has no effect on duty.
Confusing those three blocks is the source of two opposite errors: stopping too early and being unable to cost anything, or treating the statistical suffix as if it changed the amount due.
The three blocks, one by one
The first six digits derive from the WCO HS Nomenclature and the HS Convention; the next two from the Customs Tariff; the last two from the statistical nomenclature.
What each block decides
Tariff subheading (8 digits)
Statistical suffix (10 digits)
Effect on duty
Decisive: it carries a column of rates per tariff treatment.
None. Two statistical suffixes under one subheading carry the same rate.
Effect on measures
It carries the references to applicable measures and conditions.
Used for statistical tracking and sometimes for targeting.
Effect of an error
Wrong amount due, possible duty reassessment.
Inaccurate declaration, with no duty impact — which does not make it harmless.
What determines it
The terms, the notes and the general rules applied at national level.
Statistical breakdown criteria, often the unit or the presentation.
You cost a transaction at eight digits. You declare it at ten. Both statements are true at once, and both have to be held together.
The code alone does not give the rate
This is the Canadian feature most disconcerting to anyone coming from a single-column tariff. One tariff subheading carries several rates, one per tariff treatment, and the treatment retained depends on origin and on the evidence supplied.
A duty amount is only established once these four elements are fixed
| Control point | Status | What you must be able to show |
|---|---|---|
| The eight-digit tariff subheading | Required | Established by classification, independently of origin. |
| The applicable tariff treatment | Required | MFN, CUSMA, GPT, LDCT or other. Each column has its rate. |
| The origin evidence matching that treatment | Required | Each treatment has its own requirements; they are not interchangeable. |
| Any additional measures | Required | Surtax, trade-defence measure, excise: they add to the duty. |
| Rate read without checking the applicable column | Blocking | It is the most frequent cause of a gap between budget and assessment. |
The descent, step by step
- 01
Describe the goods in tariff terms
Material, function, process, presentation, degree of completion. The commercial designation identifies the article; it does not classify it.
- 02
Fix the first six digits
Section and chapter notes, then general rules 1 to 5. At this stage the reasoning is international and transposable.
- 03
Descend to the tariff subheading
General rule 6 applied to the Canadian subdivisions. Terms are compared between dashes of equal rank, never across ranks.
- 04
Choose the statistical suffix
By the breakdown criterion specific to the subheading — often the unit, the presentation or the destination. It does not change the rate.
- 05
Determine the tariff treatment
A separate decision, based on origin and its evidence. It comes after classification, never before.
- 06
Record the tariff version
The tariff is amended during the year. The consultation date is part of the decision.
What classification alone does not say
1
Classification
Which tariff subheading
2
Origin
Which tariff treatment, with what evidence
3
Value
Which base, with which adjustments
Methodological guidance appears in the Agency's memoranda, notably CBSA Memorandum D11-11-3 on applying the general rules, and CBSA Memorandum D11-4-2 on proof of origin.
Two records to open from the bottom up
8471300000Open the tariff record 8517130000Open the tariff recordCost the gap before acting
| Input | Formula | Result |
|---|---|---|
| Transactions concerned over 24 months | Declaration extract | 54 |
| Average customs value | Teaching assumption | CAD 100,000 |
| Rate gap between subheadings | 8.5% − 0% | 8.5 points |
| Gross duty exposure | 54 × 100,000 × 8.5% | CAD 459,000 |
What statistics can check
Merchandise trade data published in the Statistics Canada 2025 merchandise trade release and the Statistics Canada table 12-10-0171-01 gives the scale of a flow and helps spot an abnormally loaded line. It validates no individual classification and establishes no probability of verification.
Retention and review triggers
Keep, alongside the ten-digit number: the dated technical description, the subheading retained and the alternative rejected, the decisive general rule, the statistical suffix and its criterion, the tariff version consulted, the tariff treatment retained with its origin evidence, and the approver.
Reopen the decision if the product changes, if the supplier or origin changes, if a tariff amendment affects the subheading, or if an advance ruling or a decision under the CITT appeals guidance contradicts the analysis. Retention obligations derive from the Customs Act.