A California DOT, or CA number, is a unique identifier assigned by California’s Department of Transportation. CA numbers are unique to California and differ from USDOT numbers. You will need a California DOT number if you operate a motor carrier company in the state. Out-of-state carriers who wish to cross California state lines are often required to obtain a CA number in addition to a USDOT.
If you are not operating within the state of California or planning on crossing over into the state, you should not need a California DOT number.