Description: Methylphosphonic acid
Base HTS fields include an official source, retrieval date, and calculation trace. This page still remains a planning and broker-review prep page.
US import duty quick answer
HTS 2931.44.00.00 (Methylphosphonic acid) has a source-backed MFN base duty of 3.7%. This is not a final filing rate: unresolved policy layers are neither treated as zero nor added into a guessed total.
HTS code
2931.44.00.00
Base MFN rate
3.7%
Planning view
Known subtotal: base 3.7%; final rate unresolved
MFN base duty
3.7%This is only the USITC HTS general-rate field. It does not include Chapter 99 or trade-remedy layers.
Section 301 / Chapter 99
Review requiredDo not hard-code 7.5% or 25% from a product category or historical list. Bind the rule directly to USTR/HTS Chapter 99 sources, origin, effective dates, and exclusions.
Section 122 historical layer
Expired historical windowDo not add the expired temporary layer to a current shipment. Review it only for an applicable historical entry date against official sources.
Section 232 / product-specific remedies
Product reviewSteel, aluminum, copper, autos, semiconductors, lumber, and derivatives require current annex, origin, content, and Chapter 99 review.
AD/CVD scope
Manual scope reviewAn HTS match is only a risk signal; the written scope of the order controls legal coverage.
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Get an email when an official-source fingerprint changes, with retrieval context and a review item in your workspace. A signal is not a legal determination.
Set up a tariff change watchHTS 2931.44.00.00 corresponds to “Methylphosphonic acid.” Final classification still depends on material, use, specifications, and statistical suffix.
Description
Methylphosphonic acid
Data source and update date
Base source: USITC HTS revision feed, retrieved 2026-09-07. Additional-layer rates are not currently published.
This page publishes the base rate only. Section 301 requires direct origin, Chapter 99, effective-date, and exclusion verification.
The same HS code can produce very different planning outcomes by origin. This table compares scenarios; it is not a final filing determination.
| Origin | MFN | Section 301 | Section 122 | Section 232 | Planning view | Note | Compare in calculator |
|---|---|---|---|---|---|---|---|
| China | 3.7% | Review required | Not current | Product review | No unsupported total | Check Chapter 99, exclusions, AD/CVD, quotas, and entry date. | Compare in calculator → |
| Vietnam | 3.7% | Current-origin review | Not current | Product review | No unsupported total | A different origin changes the policy stack; do not reuse China rates. | Compare in calculator → |
| Mexico | 3.7% | Current-origin review | Not current | USMCA and product review | No unsupported total | Confirm USMCA eligibility before product-specific measures. | Compare in calculator → |
This section only publishes base HTS information with source fields attached. Base HTS and additional-duty review work stay separate so the page does not overstate unsupported composite estimates.
HTS general rate field: 3.7%
Rate-output note: only the base HTS field is shown here. Additional duties, Chapter 99 treatment, exclusions, or AD/CVD still require separate review.
Calculation method
Exact official field
Source name
USITC HTS revision feed
Retrieved date
2026-09-07
Effective date
-
Version / revision
2026-revision-18
Confidence status
official-source
Review status
Verified
The public page separates base HTS, additional layers, and public visibility. Dashed bars show a component may exist in the planning stack but is not yet source-complete enough to publish as a public rate.
Base HTS
Exact official field
Country / temporary additional-duty layer
This layer is hidden until a dated rule is directly bound to its official document, economy, HTS scope, and exclusions.
Section 301 / Chapter 99 layer
This layer is hidden until a dated rule is directly bound to its official document, economy, HTS scope, and exclusions.
Base-field precision
94%Exact official field
Source freshness
88%Inside freshness window
Public visibility
22%Still review-gated
Treat the following items as a broker/compliance review checklist, not as an automated determination. The core checks are Chapter 99, Section 301, USTR exclusions, AD/CVD, quotas or safeguards, and broker confirmation.
The entered code (2931.44.00.00) is specific enough to start a rate review, but classification still requires product facts and broker/official confirmation.
Open USITC HTS searchUse the product description when comparing material, construction, principal use, and classification rationale from rulings.
Search CBP CROSSCandidate 2931.44.00.00: Methylphosphonic acid. General duty field: 3.7%.
Open USITC HTS searchTariffsChart can apply 3.7% as a planning base duty rate. Still verify special rates, units, footnotes, and applicability.
For China-origin goods, verify Section 301 coverage, exclusions, IEEPA/other current trade-remedy FAQs, and any required Chapter 99 secondary classifications. The automated result does not determine coverage.
Open CBP Section 301 FAQSearch ACCESS/AD-CVD by country, product, commodity, case number, and HTS. Scope language controls; an HTS match is only a screening signal.
Open AD/CVD SearchVerified HTS detail pages from the same heading or chapter. Use them to compare adjacent classifications, materials, and use cases before broker review.
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
Source retrieved: 2026-09-07
These are the official-source entry points this route should open and preserve before relying on any shipment assumption.
official-source · 2026-09-18
Candidate HTS: 2931.44.00.00 Description: Methylphosphonic acid General rate field: 3.7% Simple ad-valorem rate parsed for planning: 3.7%
Open official sourceofficial-source · 2026-09-18
Search for binding CBP rulings involving similar merchandise. Capture ruling number, date, product facts, classification rationale, and whether the facts match this SKU. CROSS examples help frame broker questions but do not automatically classify your product.
Open official sourceofficial-source · 2026-09-18
For China-origin goods, verify whether the HTS classification is covered by Section 301 remedies, whether any exclusion applies, and which Chapter 99 secondary classification should be reported. Do not infer coverage from the base HTS line alone.
Open official sourceofficial-source · 2026-09-18
Check USTR Section 301 tariff actions, exclusion notices, and extension status. Save the specific list/exclusion evidence if a product exclusion is claimed.
Open official sourceofficial-source · 2026-09-18
Search Commerce ACCESS/AD-CVD resources by country, product, case number, HTS number, and commodity. AD/CVD scope can be broader or narrower than an exact HTS match; ask the broker whether a scope ruling or specialist review is needed.
Open official sourceofficial-source · 2026-09-18
Review whether any current CBP trade-remedy FAQ, CSMS message, or Chapter 99 note applies in addition to Section 301, base duty, AD/CVD, or other measures. This is a prompt for professional review, not an automated determination.
Open official source