# 2025-03991: Southern Border Tariffs Tweaked to Spare Mexican Auto Parts

2025-03991, Amendment to Duties To Address the Flow of Illicit Drugs Across Our Southern Border, is a Federal Register presidential document from Executive Office of the President published 2025-03-11, effective 2025-03-07; PRIA reads it as touching household money (as of 2026-11-03).

- Canonical: https://policyrisk.com/federal-register/2025-03991
- As of: 2026-11-03
- Plain-text twin of the page above; the HTML and this file carry the same facts.

## Facts
- Document number: 2025-03991
- Title: Amendment to Duties To Address the Flow of Illicit Drugs Across Our Southern Border
- Type: Presidential Document
- Agencies: Executive Office of the President
- Citation: 90 FR 11787
- Published: 2025-03-11
- Effective: 2025-03-07
- Comments close: not stated
- Significant: no
- Touches household money: yes
- Regulation identifier numbers: none
- Last updated: 2026-11-03

## In one line

Southern Border Tariffs Tweaked to Spare Mexican Auto Parts

## Summary

This update changes some tariffs on goods from Mexico to help protect American car workers and keep supply chains running smoothly. Certain automotive parts will no longer face extra taxes, and the tariff on potash drops from 25% to 10%. These changes started on March 7, 2025, aiming to balance border security with economic stability.

## Effects PRIA read

- Mexican-made Auto Parts Exempted: benefit, medium. Automotive articles that qualify as goods of Mexico under general note 11 to the Harmonized Tariff Schedule of the United States (HTSUS) — including treatments in subchapters XXIII of chapter 98 and XXII of chapter 99 — will not face the additional ad valorem duty imposed by section 2(a) of Executi…
- Potash Tariff Cut to 10%: benefit, high. The additional rate of duty on potash that is not covered by subsection (a) is reduced from 25 percent to 10 percent. This reduction is effective for goods entered for consumption or withdrawn from warehouse for consumption on or after 12:01 a.m. Eastern Standard Time on March 7, 2025.

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## Sources
- [2025-03991 on federalregister.gov](https://www.federalregister.gov/documents/2025/03/11/2025-03991/amendment-to-duties-to-address-the-flow-of-illicit-drugs-across-our-southern-border)
- [2025-03991 as published (PDF)](https://www.govinfo.gov/content/pkg/FR-2025-03-11/pdf/2025-03991.pdf)

## Related
- [Previous: 2025-03990, Amendment to Duties To Address the Flow of Illicit Drugs Across Our Northern Bo…](https://policyrisk.com/federal-register/2025-03990)
- [Next: 2025-03992, Establishment of the Strategic Bitcoin Reserve and United States Digital Asset…](https://policyrisk.com/federal-register/2025-03992)
- [All Federal Register documents](https://policyrisk.com/federal-register)

Source: PRIA, https://policyrisk.com/federal-register/2025-03991 (as of 2026-11-03).