Section 5011 Of Article 1.5. Cancellation Of Assessments On State-assessed Property From California Revenue And Taxation Code >> Division 1. >> Part 9. >> Chapter 4. >> Article 1.5.

. All or any portion of any assessment of state-assessed property heretofore or hereafter levied may, on satisfactory proof, be canceled by the board if it was made:
  (a) More than once.
  (b) Erroneously or illegally.
  (c) On improvements when the improvements did not exist on the lien date.