California Code, Vehicle Code - VEH § 22511.6

(1) When the department is satisfied that the placard was fraudulently obtained or erroneously issued.

(2) When the department determines that the required fee has not been paid and the fee is not paid upon reasonable notice and demand.

(3) When the placard could have been refused when last issued or renewed.

(4) When the department determines that the owner of the placard has committed any offense described in Section 4461 or 4463, involving the placard to be canceled or revoked.

(5) When the department determines that the owner of the placard is deceased.