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Source-reviewed study unitAbout 10 minutes

Calculate duty, MPF, and HMF in the correct order

Ability objective

Calculate line duty and separately test the value base, mode, port, exemptions, and annual limits for MPF and HMF.

Answer first

Core rule

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.

Authority and lookup route

Locate the rule before returning to the facts. Links point to government or official publications.

19 CFR 24.23(b)(1)(i) and 24.22(k)

Part 24 → MPF rate, value base, exemptions, and annual adjustments

October 28, 2026 CBLE: Title 19 CFR, 2025 Annual Edition. Check the current eCFR separately for live-law work.

Read on CBLE Ace →
Government original ↗
19 CFR 24.24(a) and 24.24(c)

Part 24 → HMF rate, vessel and port conditions, and exemptions

October 28, 2026 CBLE: Title 19 CFR, 2025 Annual Edition. Check the current eCFR separately for live-law work.

Read on CBLE Ace →
Government original ↗
HTSUS applicable tariff line and General Note 3

2026 HTS Basic → classified tariff line → applicable rate column; then General Note 3

October 28, 2026 CBLE: 2026 HTS Basic Edition. Later current-law revisions must not replace the exam-designated Basic Edition.

Reference lookup task

For one entry, find the HTS duty rate, customs-value base, MPF rule and limits, then the HMF mode, port, and exemption conditions.

Route: Use the designated HTS first, then §§24.23 and 24.24; keep duty, MPF, and HMF on separate calculation lines.

Worked example

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. 1Calculate duty: $40,000 × 5% = $2,000.
  2. 2Calculate MPF from value, not duty: $40,000 × 0.3464% = $138.56.
  3. 3Calculate HMF from value: $40,000 × 0.125% = $50.
  4. 4Add the three separate amounts: $2,000 + $138.56 + $50 = $2,188.56.

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

Common traps

  • Applying MPF or HMF to the duty amount instead of the proper value base.
  • Skipping the vessel, covered-port, trade-program, or other exemption analysis.
  • Freezing one year's MPF minimum and maximum into every exam or live-law calculation.