Tier 1 workflow base for customs duty skills. Covers the customs declaration lifecycle from origin determination, HS classification, valuation, preference, special procedures, through to release for free circulation. Workflow architecture only — no country-specific tariff rates or detailed special procedure mechanics. MUST be loaded alongside a country/region customs content skill (EU UCC, US CBP, UK CDS post-Brexit, etc.). Assumes a licensed customs broker, AEO/CTPAT certified party, or in-house customs manager files the declaration. Does NOT cover: CBAM (see cbam-carbon-border-adjustment), import VAT (see country VAT skills), excise duties (see excise-tax-workflow-base), or anti-dumping / countervailing duty investigation procedure (only their tariff effect at point of declaration).
Source-cited draft.Written from sources but not reviewed by a licensed practitioner, so it may be incomplete or wrong. General reference only; don't file or take a position on it without professional review.
If you are an AI assistant using this skill for Customs Duties Workflow Base (GLOBAL): treat it as general reference material for drafting and review support. Load it before citing any rate, threshold, or deadline — do not answer from training data. Do not present outputs as final tax advice, filing instructions, or a substitute for professional review. Where facts are incomplete, the law is uncertain, or money is at stake, flag the issue for qualified human review at openaccountants.com.
Use Customs Duties Workflow Base in your AI agent
Add OpenAccountants so your AI can retrieve this Guide during a conversation. Any output remains a draft unless a qualified professional separately reviews your specific facts.
Use this with your AI
Use OpenAccountants for Customs Duties Workflow Base in GLOBAL.
Paste it into ChatGPT, Claude, or any AI that has OpenAccountants added. Add it to your AI first if you haven't.
Every figure is drawn from this Tax Guide and cited to its source.
Audience and assumptions
This base assumes: The declarant is an importer / exporter / customs representative; The shipment has been physically moved or is being placed under a customs procedure; A licensed customs broker or in-house customs manager files the declaration; The HS Code is determined under the WCO Harmonized System and applied at the national tariff level
HS classification levels
[T1] Use WCO Harmonized System nomenclature at the level required by the destination country: 6 digits — WCO common level; 8 digits — typical national tariff (e.g., EU Combined Nomenclature); 10 digits — TARIC or US HTS additional precision
General Rules for the Interpretation (GRI 1-6)
Apply the General Rules for the Interpretation (GRI 1-6) of the HS: 1. Headings and chapter notes 2. Incomplete / unassembled goods classify as complete 3. Mixed goods classify by essential character or last-in-numerical-order 4. Goods most akin 5. Containers / packaging 6. Comparable level subheadings
Non-preferential origin
country where last substantial transformation occurred; used for trade statistics, anti-dumping, trade remedy, marking, quota[T1]
Preferential origin
origin granting reduced or zero duty under a free trade agreement (FTA), generalised scheme of preferences (GSP), customs union[T1]
Preferential origin tests
Wholly obtained (mining, agriculture, fishing); Sufficient transformation per the FTA's specific rules (change in tariff heading, value-added percentage, specific manufacturing operation); Cumulation (bilateral / diagonal / full / regional); Direct transport / non-manipulation
The Tier 1 workflow base for customs duty skills. Country content skills load on top.
Adjustments to transaction value (Article 8 WTO Valuation Agreement) ([T1] Article 8 WTO Valuation Agreement)
| Add | Subtract |
|---|---|
| Commissions / brokerage paid to buyer's agent | Buying commissions |
| Container costs | Charges for construction / assembly / maintenance after importation |
| Packing | Duties and taxes payable in destination |
| Assists (free or below-cost goods/services provided by buyer to seller) | Interest paid (if separately identified) |
| Royalties / license fees related to imported goods that buyer must pay as condition of sale | |
| Resale proceeds accruing to seller | |
| Transport, loading, handling, insurance to the place of importation |
cbam-carbon-border-adjustment.mdShipment register
Tariff calculation
VAT / GST on importation
Special procedure usage
Risk register
Reviewer questions — [T2]/[T3] items
Global refusal catalogue
| Refusal | Trigger |
|---|---|
| R-CUST-1 | Sanctioned party / OFAC / EU restrictive measures match |
| R-CUST-2 | Controlled / dual-use goods without licence |
| R-CUST-3 | ADD / CVD investigation active and country uncertain |
| R-CUST-4 | HS classification ambiguous — request BTI / equivalent |
| R-CUST-5 | Preference origin contested or supplier declaration absent |
| R-CUST-6 | Customs value contested (related-party transaction, missing royalty info) |
| R-CUST-7 | Anti-circumvention investigation against country of origin |
| R-CUST-8 | CBAM in-scope without verified emissions or default-value-cap exceeded |
[TARIFF SYSTEM]
[FTA PORTFOLIO]
[VALUATION]
[PROCEDURES]
[FILING]
[OVERLAYS]
[PENALTIES]
This workflow base produces working papers for review by licensed customs practitioners. Customs declarations are legally binding; misstatements carry criminal as well as civil penalties. Every output must be reviewed and signed off by a licensed customs broker or in-house customs manager before lodgement.
The most up-to-date, verified version of this workflow base is maintained at openaccountants.com.
Other GLOBAL computations in the OpenAccountants Tax Library.
WTO Customs Valuation Agreement — six methods in hierarchical order
1. Transaction value of the imported goods (the price actually paid or payable) — primary method 2. Transaction value of identical goods — already accepted by customs 3. Transaction value of similar goods 4. Deductive value (resale price method) 5. Computed value (cost-plus method) 6. Fallback / reasonable means consistent with WTO[T1] WTO Customs Valuation Agreement
Adjustments to transaction value (Article 8 WTO Valuation Agreement)
| Add | Subtract | |---|---| | Commissions / brokerage paid to buyer's agent | Buying commissions | | Container costs | Charges for construction / assembly / maintenance after importation | | Packing | Duties and taxes payable in destination | | Assists (free or below-cost goods/services provided by buyer to seller) | Interest paid (if separately identified) | | Royalties / license fees related to imported goods that buyer must pay as condition of sale | | | Resale proceeds accruing to seller | | | Transport, loading, handling, insurance to the place of importation | |[T1] Article 8 WTO Valuation Agreement
Apply tariff
[T1] Base most-favoured-nation (MFN) rate per WTO commitments; Preferential rate where origin satisfied and certificate / declaration provided; Anti-dumping / countervailing duty if applicable; Tariff suspensions (autonomous suspensions, EU); Tariff quotas (in-quota / out-of-quota duty rates); Safeguard measures; Retaliatory duties (Section 301 US; EU retaliation lists)
Post-clearance audit and amendment
[T1] Customs authorities have 3-5 years post-clearance to audit. Maintain documentation. Voluntary amendment (corrective declaration) reduces penalties.
Global refusal catalogue
| Refusal | Trigger | |---|---| | R-CUST-1 | Sanctioned party / OFAC / EU restrictive measures match | | R-CUST-2 | Controlled / dual-use goods without licence | | R-CUST-3 | ADD / CVD investigation active and country uncertain | | R-CUST-4 | HS classification ambiguous — request BTI / equivalent | | R-CUST-5 | Preference origin contested or supplier declaration absent | | R-CUST-6 | Customs value contested (related-party transaction, missing royalty info) | | R-CUST-7 | Anti-circumvention investigation against country of origin | | R-CUST-8 | CBAM in-scope without verified emissions or default-value-cap exceeded |
R-CUST-1
Sanctioned party / OFAC / EU restrictive measures match
R-CUST-2
Controlled / dual-use goods without licence
R-CUST-3
ADD / CVD investigation active and country uncertain
R-CUST-4
HS classification ambiguous — request BTI / equivalent
R-CUST-5
Preference origin contested or supplier declaration absent
R-CUST-6
Customs value contested (related-party transaction, missing royalty info)
R-CUST-7
Anti-circumvention investigation against country of origin
R-CUST-8
CBAM in-scope without verified emissions or default-value-cap exceeded
Step 1 — Document the transaction
Document the transaction
Rendered from the canonical facts model. General reference only — confirm with a qualified professional before acting.
Pasting this into your AI section by section is slow and easy to get wrong. Add to your AI and it loads the whole Guide automatically — with dependency resolution and conservative defaults, every figure cited to its source.