Duty Stack API

Live

The base rate plus every Chapter 99 line for an HTS code, origin and entry date, with citations and the duty in dollars.

Section 301, 232, IEEPA, Section 122 and other Chapter 99 measures as of any entry date in the coverage. One line, a batch of up to 200, or one code from many origins.

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At a glance

Status: Live
Endpoints: POST /v1/tariffs/duty-stack
POST /v1/tariffs/duty-stack/batch
POST /v1/tariffs/compare-origins
Cost: 10 units (each endpoint)
MCP tools: tariffs_duty_stack
tariffs_duty_stack_batch
tariffs_compare_origins
Data: Tariffs dataset 1.0.0, built 2026-10-10.

Try it

Choose an endpoint and a sample, change the parameters, and send. Without a key the public demo answers the sample requests (marked demo, not counted against any quota, limited per IP address). With your key, or your account when you are signed in, any values work and the call counts against your plan. A key stays in this page's memory: it is never stored. Get a free key.

Recorded answer of the real API on the current data for this sample (long arrays trimmed).

HTS 6112.19.40.50 from CN, entered 2025-08-20

Total duty41%= $4,100.00 on $10,000.00

Not included

Merchandise processing fee (MPF) and harbor maintenance fee (HMF)
Antidumping and countervailing duties
Duties on a specific (per unit) basis, which need the quantity

Duty stack, line by line
Line	Rate	Running total	Duty
Base rate column 1 General	3.5%	3.5%	$350.00
9903.01.24 IEEPA	+20%	23.5%	$2,000.00
9903.01.25 IEEPA	+10%	33.5%	$1,000.00
9903.88.15 Section 301	+7.5%	41%	$750.00
Total duty	41%		$4,100.00

Response 200POST/v1/tariffs/duty-stack

{
  "data": {
    "qid": null,
    "input": {
      "hts10": "6112194050",
      "origin": "CN",
      "entry_date": "2025-08-20",
      "export_date": null,
      "mode": "vessel",
      "declared_attributes": {}
    },
    "hts_revision_in_force": {
      "release": "2025HTSRev19",
      "valid_from": "2025-08-18",
      "valid_to": "2025-08-26",
      "chapter99_url": "https://hts.usitc.gov/reststop/file?release=2025HTSRev19&filename=Chapter%2099",
      "change_record_url": "https://hts.usitc.gov/reststop/file?release=2025HTSRev19&filename=Change%20Record",
      "source": "ruledata/revisions.json (USITC releaseList)"
    },
    "base_mfn": {
      "hts10": "6112.19.4050",
      "general_rate_text": "3.5%",
      "rate_type": "ad_valorem",
      "ad_valorem_equivalent": 3.5,
      "applied_rate_text": "3.5%",
      "applied_basis": "column 1 General",
      "applied_ad_valorem_pct": 3.5,
      "citations": [
        {
          "type": "USITC HTS (adjudicated MFN group)",
          "release": "2025HTSRev19",
          "locator": "HTS 6112.19.4050, column 1 General, release 2025HTSRev19",
          "url": "https://hts.usitc.gov/reststop/file?release=2025HTSRev19&filename=finalCopy",
          "rule_file": "ruledata/mfn_intervals.jsonl"
        }
      ]
    },
    "declared_attributes_used": [],
    "defaults_applied": [
      "cbp_transshipment_determination=false (policy_default)",
      "humanitarian_donation_1702b2=false (policy_default)"
    ],
    "chapter99_lines": [
      {
        "heading": "9903.01.24",
        "rule_id": "IEEPA_CN_FENT_20",
        "group": "ieepa",
        "authority": "IEEPA; EO 14195 as amended by EO 14228 (90 FR 11463)",
        "rate_text": "+20% ad valorem on the value of the article",
        "rate_pct": 20,
        "rate_formula": null,
        "valuation_basis": "full customs value",
        "share_of_value": 1,
        "amount_pct": 20,
        "amount_formula": "20",
        "specific_rate": null,
        "status_hint": null,
        "citations": [
          {
            "type": "cbp_csms",
            "id": "CSMS #64299816",
            "url": "https://content.govdelivery.com/accounts/USDHSCBP/bulletins/3d52328",
            "quote": "entered for consumption, or withdrawn from warehouse for consumption, on or after 12:01 a.m. eastern standard time on March 4, 2025: 9903.01.24: All imports of articles that are products of China and …"
          },
          {
            "type": "federal_register",
            "id": "EO 14228, 90 FR 11463",
            "url": "https://www.federalregister.gov/documents/2025/03/07/2025-03775/further-amendment-to-duties-addressing-the-synthetic-opioid-supply-chain-in-the-peoples-republic-of",
            "quote": "section 2(a) of Executive Order 14195 is hereby amended by striking the words “10 percent” and inserting in lieu thereof the words “20 percent”. Sec. 3 . General Provisions. (a) Nothing in this order …"
          },
          "… 3 more"
        ]
      },
      {
        "heading": "9903.01.25",
        "rule_id": "RECIP_BASE_10_W5",
        "group": "ieepa",
        "authority": "IEEPA; EO 14257 as amended by EO 14326 (90 FR 37963) and later orders",
        "rate_text": "+10% ad valorem on the value of the article",
        "rate_pct": 10,
        "rate_formula": null,
        "valuation_basis": "full customs value",
        "share_of_value": 1,
        "amount_pct": 10,
        "amount_formula": "10",
        "specific_rate": null,
        "status_hint": null,
        "citations": [
          {
            "type": "cbp_csms",
            "id": "CSMS #65829726",
            "url": "https://content.govdelivery.com/accounts/USDHSCBP/bulletins/3ec7b5e",
            "quote": "Goods of China, including Hong Kong and Macau, continue to be subject to the 10% reciprocal tariff under heading 9903.01.25. EXEMPTIONS The following HTSUS classifications apply to products that are e…"
          },
          {
            "type": "usitc_hts",
            "id": "HTSUS 2026HTSRev3, Chapter 99 heading 9903.01.25",
            "url": "https://hts.usitc.gov/reststop/file?release=2026HTSRev3&filename=Chapter%2099",
            "quote": "9903.01.25: Articles the product of any country, except for products described in headings 9903.01.26–9903.01.33, 9903.02.02–9903.02.91, 9903.96.01, and 9903.96.02, and except as provided for in headi…"
          },
          "… 3 more"
        ]
      },
      "… 1 more"
    ],
    "not_applied": [
      {
        "heading": "9903.02.01",
        "rule_id": "RECIP_TRANSSHIP_40",
        "group": "ieepa",
        "authority": "IEEPA; EO 14326 sec.3",
        "reason": "condition cbp_transshipment_determination == true not met (cbp_transshipment_determination = false, policy_default) - available only if claimed/declared",
        "citation": [
          {
            "type": "usitc_hts",
            "id": "HTSUS 2026HTSRev3, Chapter 99 heading 9903.02.01",
            "url": "https://hts.usitc.gov/reststop/file?release=2026HTSRev3&filename=Chapter%2099",
            "quote": "9903.02.01: Articles the product of any country determined by U.S. Customs and Border Protection to have been transshipped to evade applicable duties under section 2 of Executive Order [Insert EO numb…"
          }
        ]
      },
      {
        "heading": "9903.01.20",
        "rule_id": "IEEPA_CN_FENT_10_2025FEB",
        "group": "ieepa",
        "authority": "IEEPA; EO 14195 (90 FR 9121) as amended by EO 14200",
        "reason": "terminated/expired: in force for entries 2025-02-04..2025-03-03",
        "citation": [
          {
            "type": "usitc_hts",
            "id": "HTSUS 2025HTSRev1, Chapter 99 heading 9903.01.20",
            "url": "https://hts.usitc.gov/reststop/file?release=2025HTSRev1&filename=Chapter%2099",
            "quote": "9903.01.20: Except for products described in headings 9903.01.21, 9903.01.22, or 9903.01.23 articles the product of China and Hong Kong, as provided for in U.S. note 2(s) to this subchapter | General:…"
          }
        ]
      },
      "… 8 more"
    ],
    "total": {
      "ad_valorem_pct": 41,
      "formula": "41",
      "specific_components": []
    },
    "status": "COMPUTED",
    "review_flags": [],
    "ieepa": {
      "ieepa_duty_paid": true,
      "ieepa_lines": ["9903.01.24", "9903.01.25"],
      "ieepa_pct_of_value": 30,
      "refund_eligible": true,
      "refund_basis": "IEEPA duties are no longer collected for entries on/after 12:00 a.m. ET 2026-02-24 (EO 14389; CBP CSMS #67834313). CBP refunds IEEPA duties paid on earlier entries through a CAPE Declaration in ACE (C…",
      "needs_attributes_for_path": ["liquidation_status", "liquidation_date", "… 1 more"],
      "sources": [
        {
          "type": "CBP CSMS",
          "id": "CSMS #67834313",
          "url": "https://content.govdelivery.com/accounts/USDHSCBP/bulletins/40b11c9"
        },
        {
          "type": "Federal Register",
          "id": "EO 14389, Ending Certain Tariff Actions (91 FR 9437)",
          "url": "https://www.federalregister.gov/documents/2026/02/25/2026-03832/ending-certain-tariff-actions"
        },
        "… 1 more"
      ]
    },
    "trace": [
      "Entry date 2025-08-20 -> 2025HTSRev19 (valid 2025-08-18..2025-08-26).",
      "11 rules match origin CN and HTS 6112.19.4050 on the entry date (34 more outside their date window)."
    ],
    "plausibility": [],
    "engine": {
      "name": "engine-ts (datasets/tariffs)",
      "rules_version": "1.0.0",
      "coverage": { "from": "2025-01-01", "to": "2026-10-09" },
      "parity": "identical to the Python reference engine on 500 test and 3,000 stress queries (datasets/tariffs/engine-ts/PARITY.md)"
    },
    "amounts": {
      "entered_value_usd": 10000,
      "base": { "rate_text": "3.5%", "ad_valorem_pct": 3.5, "duty_usd": 350 },
      "chapter99_lines": [
        {
          "heading": "9903.01.24",
          "rule_id": "IEEPA_CN_FENT_20",
          "amount_pct": 20,
          "duty_usd": 2000
        },
        {
          "heading": "9903.01.25",
          "rule_id": "RECIP_BASE_10_W5",
          "amount_pct": 10,
          "duty_usd": 1000
        },
        "… 1 more"
      ],
      "total": { "ad_valorem_pct": 41, "duty_usd": 4100, "basis": "sum of the rounded lines" },
      "not_included": [
        "Merchandise processing fee (MPF) and harbor maintenance fee (HMF)",
        "Antidumping and countervailing duties",
        "… 1 more"
      ],
      "method": "duty = entered value x percent / 100, rounded to the cent (code, exact decimal arithmetic), for each line whose percent is a number on this entry date; the total is the sum of the rounded lines, as an…"
    }
  },
  "meta": {
    "request_id": "req_…",
    "api_version": "1",
    "dataset": "tariffs",
    "dataset_version": "1.0.0",
    "dataset_built_at": "2026-10-10T16:05:28Z",
    "data_status": "released",
    "sources": [
      {
        "id": "usitc_harmonized_tariff_schedule_chapter",
        "name": "USITC Harmonized Tariff Schedule (Chapter 99 PDFs, Change Records, releaseList, exportList REST)",
        "url": "https://hts.usitc.gov/",
        "licence": "U.S. Government work, public domain (17 U.S.C. 105)",
        "commercial_redistribution_ok": true,
        "retrieved": "2026-10-09/2026-10-10"
      },
      {
        "id": "federal_register_proclamations_executive",
        "name": "Federal Register (proclamations, executive orders, USTR/Commerce notices)",
        "url": "https://www.federalregister.gov/",
        "licence": "U.S. Government work, public domain (17 U.S.C. 105)",
        "commercial_redistribution_ok": true,
        "retrieved": "2026-10-09/2026-10-10"
      },
      "… 3 more"
    ],
    "provenance_note": "Every value carries provenance (source, id or URL, retrieval date; method and confidence where an AI judged). Calculations list their inputs and method.",
    "disclaimer": "Reference data and calculations from HTS codes you supply. Not classification advice and not a filing: entry filings need a licensed customs broker (CBP HQ H350722).",
    "usage": "…"
  }
}

1Each line carries its citations, with the quoted text
2Pin and diff: the version is also in the X-Dataset-Version header

curlPOST/v1/tariffs/duty-stack

curl -s -X POST "https://api.htscalculator.com/demo/v1/tariffs/duty-stack" \
  -H "Content-Type: application/json" \
  -d '{"hts10":"6112194050","origin":"CN","entry_date":"2025-08-20","entered_value_usd":10000}'

Endpoints

Endpoints of the Duty Stack API
Endpoint	What it does	Cost	MCP tool	Documentation
POST /v1/tariffs/duty-stack	Duty stack for an HTS code, origin and date	10 units	tariffs_duty_stack	Docs
POST /v1/tariffs/duty-stack/batch	Duty stacks for many lines	10 units per line	tariffs_duty_stack_batch	Docs
POST /v1/tariffs/compare-origins	Compare origins for one HTS code	10 units per distinct origin	tariffs_compare_origins	Docs

What is included

Rates, valuation basis, share of value and totals, with citations per line
Duty in dollars when you send the entered value
Batch of up to 200 lines, and origin comparison
Branches on undeclared facts (metal content, USMCA and others)
Merchandise processing and harbor maintenance fees Coming soon

How it differs

Lines considered and not applied are listed with the reason.
The dataset version on every response, so you can pin and diff.
A reference calculation from the code you supply: we never classify goods.

Plans

One key and one plan cover every HTS Calculator product, this one included. Free: 2,500 units a month (250 calls of /v1/tariffs/duty-stack). Developer $49 and Pro $249 a month. Caching inside your product is allowed, and so is use by AI agents. Plans and units.

Status: Live. All products.