Clean Truck Check deadlines and testing windows

California-registered vehicles

Deadlines follow the DMV registration expiration date. Trucks on the semi-annual cycle get two deadlines a year: the registration expiration month and the month six months before it. Because compliance is tied to registration, an unresolved CTC obligation can block renewal.

Out-of-state vehicles: VIN last digit

Vehicles registered outside California are scheduled by the last digit of the VIN, on a semi-annual cycle:

Motorhomes and agricultural vehicles

These test once per year rather than semi-annually, on the anniversary of the registration expiration.

The 90-day testing window

A test submitted within the 90 days before a deadline satisfies that deadline. Testing too early can mean the result does not count toward the upcoming compliance date, so shops should schedule inside the window — not months ahead of it.

How CTC Tracker computes your dates

When you add a vehicle you enter VIN, plate state, vehicle type, engine year, and registration expiration. The app derives the test method and the next CTC due date automatically, rolls the deadline forward when a passing test is logged inside the window, and keeps a missed deadline flagged as overdue until it is satisfied. Reminders fire at 90, 30, and 7 days, and again the day it is due.

New to the program? Start with the Clean Truck Check guide.