Every approved US content figure for a Canadian or Mexican built car stops working on December 1, whatever expiry date is printed on it, and the paperwork to replace it is due September 30

Six weeks.

That is the window importers of USMCA qualifying automobiles now have to refile the paperwork that keeps the 25 percent section 232 tariff off the American content of their cars. The Commerce Department put the notice on public inspection on Tuesday morning. It takes effect on publication, scheduled for Wednesday.

What lapses

Under the procedures set in May 2025, an approved US content determination was good for six months from the day it was issued. Those approvals now expire on a common date instead. Every determination granted under the old notice stops applying to cars imported on or after December 1, 2026, and the notice says so in terms: regardless of model year, and regardless of any expiration date set out in the determination itself.

To cover imports after that date, an importer has to file again, and Commerce wants the documentation by September 30 to be sure of processing it in time. The determination that comes back runs until December 1, 2027. From then the cycle is annual, with the following year's filing due by September 1.

Why the dates moved

The reason is alignment rather than policy. When the President extended section 232 tariffs to medium and heavy duty vehicles, their parts and buses last October, the proclamation observed that the part suppliers overlap heavily with the car industry and directed that the two tariff systems be conformed. Commerce built the truck and bus procedures in February on an annual cycle with an autumn filing date. This notice pulls cars onto the same calendar.

An importer whose sourcing changes in a way that lowers US content must tell Commerce promptly and ask for a new determination. If the change raises US content, telling Commerce is optional.

The penalty clause did not change

It was carried over unaltered, and it is the reason the certification is signed by a chief financial officer or a general counsel. If Customs finds the declared US content overstated, or inconsistent with the figure the Secretary approved, the full 25 percent applies to the entire value of every car in that model line imported by that importer. Retroactively, as far back as April 3, 2025 where the law allows. Prospectively, until the importer corrects it and Customs verifies the correction.

One thing the notice does not do is set up the equivalent process for automobile parts. The 2025 proclamation contemplates one. This document says plainly that it is not this.