From time to time, close examination of a client’s assessment reveals that it is partially or entirely illegal. By this we mean that the assessment should be corrected because the basis upon which it was set was improper, regardless of whether the value seems appropriate for the property. Proceedings to challenge an illegal assessment are somewhat different from certiorari proceedings, though they have much in common. Perhaps the most common example of an illegal assessment is known as “selective reassessment”, or “welcome stranger”, in which the Assessor has increased a property’s assessment based on a recent purchase price even though no improvements were made and no general revaluation has occurred. We will investigate the circumstances of any assessment increase and, where appropriate, pursue a reduction based upon grounds of illegality.