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Duty, MPF & HMF Calculations

Separate customs value, tariff rates, merchandise processing fee, harbor maintenance fee, exemptions, and annual limits.

19 CFR 24.2319 CFR 24.242026 HTSUS Basic Edition

Structured from CBP-designated exam references; confirm the editions approved for your exam sitting.

The textbook layer behind Study Map

From learning route to full explanation

Duty, merchandise processing fee, and harbor maintenance fee use different legal bases and eligibility tests. This guide separates rate, value or quantity, vessel and port facts, exemptions, and annually adjusted limits before combining the amounts.

Study Map tells you what to learn and in what order; this page explains the rules, decision method, and boundaries. Reading completion is not proof of mastery.

Textbook chapter 1

Calculate duty, MPF, and HMF in the correct order

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Answer first

Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Answer first: calculate duty from the proper customs value or statutory quantity and the exam-designated HTS rate. For a formal entry, MPF is generally 0.3464 percent of the §1401a value, subject to exemptions and annually adjusted minimum and maximum amounts. HMF is 0.125 percent of value only for covered commercial-vessel cargo and ports, subject to its exemptions. Do not apply either percentage to the duty amount. October 2026 answers use the 2026 HTS Basic and 2025 Annual CFR; current rates and annually adjusted fee caps require a separate live-law check.

Rule breakdown

Answer first: calculate duty from the proper customs value or statutory quantity and the exam-designated HTS rate. For a formal entry, MPF is generally 0.3464 percent of the §1401a value, subject to exemptions and annually adjusted minimum and maximum amounts. HMF is 0.125 percent of value only for covered commercial-vessel cargo and ports, subject to its exemptions. Do not apply either percentage to the duty amount. October 2026 answers use the 2026 HTS Basic and 2025 Annual CFR; current rates and annually adjusted fee caps require a separate live-law check. The learning objective is to calculate line duty and separately test the value base, mode, port, exemptions, and annual limits for MPF and HMF.; exceptions and triggering facts must be identified before calculation or conclusion.

Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Navigate the controlling material through Part 24 → MPF rate, value base, exemptions, and annual adjustments; Part 24 → HMF rate, vessel and port conditions, and exemptions; 2026 HTS Basic → classified tariff line → applicable rate column; then General Note 3. Record the decisive text and fact rather than relying on memory or a search snippet.

Decision path

  1. 1

    Set the legal gate for Calculate duty, MPF, and HMF in the correct order

    Calculate line duty and separately test the value base, mode, port, exemptions, and annual limits for MPF and HMF. Separate the controlling trigger from descriptive labels, then list the facts that could activate an exception or a different legal path.

  2. 2

    Prove the rule in 19 CFR 24.23(b)(1)(i) and 24.22(k)

    For one entry, find the HTS duty rate, customs-value base, MPF rule and limits, then the HMF mode, port, and exemption conditions. Use this route: Use the designated HTS first, then §§24.23 and 24.24; keep duty, MPF, and HMF on separate calculation lines.. Preserve the exact subsection, field instruction, note, or rate line that supports the answer.

  3. 3

    Test the boundary of Calculate duty, MPF, and HMF in the correct order

    Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Apply that boundary to the stated facts, identify the fact that would reverse the result, and only then adopt the worked-example conclusion: The stated total is $2,188.56, subject to the problem's no-exemption and within-limits assumptions.

Worked example

Scenario: Customs value is $40,000, the ad valorem duty rate is 5 percent, and a formal vessel entry unloads at a covered port with no fee exemption. The raw MPF falls within the applicable annual limits.

  1. 1.Calculate duty: $40,000 × 5% = $2,000.
  2. 2.Calculate MPF from value, not duty: $40,000 × 0.3464% = $138.56.
  3. 3.Calculate HMF from value: $40,000 × 0.125% = $50.
  4. 4.Add the three separate amounts: $2,000 + $138.56 + $50 = $2,188.56.
  5. 5.Boundary check: change one decisive fact identified by this research task—For one entry, find the HTS duty rate, customs-value base, MPF rule and limits, then the HMF mode, port, and exemption conditions.—and explain whether the conclusion would change under 19 CFR 24.23(b)(1)(i) and 24.22(k); 19 CFR 24.24(a) and 24.24(c); HTSUS applicable tariff line and General Note 3.

Conclusion: The stated total is $2,188.56, subject to the problem's no-exemption and within-limits assumptions.

Common traps and corrections

× Applying MPF or HMF to the duty amount instead of the proper value base.

This shortcut fails because “Applying MPF or HMF to the duty amount instead of the proper value base.” skips a controlling distinction. Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Re-run the source route in Use the designated HTS first, then §§24.23 and 24.24; keep duty, MPF, and HMF on separate calculation lines. and state the decisive fact before selecting the result.

× Skipping the vessel, covered-port, trade-program, or other exemption analysis.

This shortcut fails because “Skipping the vessel, covered-port, trade-program, or other exemption analysis.” skips a controlling distinction. Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Re-run the source route in Use the designated HTS first, then §§24.23 and 24.24; keep duty, MPF, and HMF on separate calculation lines. and state the decisive fact before selecting the result.

× Applying Calculate duty, MPF, and HMF in the correct order without proving both the decisive fact and the controlling source edition.

Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Navigate the controlling material through Part 24 → MPF rate, value base, exemptions, and annual adjustments; Part 24 → HMF rate, vessel and port conditions, and exemptions; 2026 HTS Basic → classified tariff line → applicable rate column; then General Note 3. Record the decisive text and fact rather than relying on memory or a search snippet. For the October 2026 CBLE, use the designated edition; for live work, separately date and verify the current source rather than blending the two lanes.

Frequently asked questions

Which fact controls first when applying Calculate duty, MPF, and HMF in the correct order?

Compute ordinary duty from the correct customs-value or quantity base and the designated HTS rate. Apply MPF and HMF to their own statutory bases only after testing entry type, vessel and port facts, program exemptions, and annually adjusted limits. Start with 19 CFR 24.23(b)(1)(i) and 24.22(k), identify the trigger and any exception, and use the decision path before calculating or choosing a familiar label.

Where should I verify Calculate duty, MPF, and HMF in the correct order for the exam and for live work?

Use the cited exam-edition source cards for the October 2026 CBLE and preserve their pinpoint text. For a live transaction, separately re-check the current statute, eCFR, HTS, or CBP operational source listed for this chapter; a newer source does not silently rewrite the exam edition.

Official sources and editions

Key Terms

Ad Valorem Duty|从价税
Merchandise Processing Fee|商品处理费
Harbor Maintenance Fee|港口维护费
Fee Base|费用计费基础
Back to Knowledge BaseUpdated 2026-08-19