The State Division of Taxation, with local assessors, annually conduct a statewide year sales survey. They investigate most real property transfers. Sale value is compared to assessed value individually to determine an average level of assessment in a municipality. An average ratio is developed from all arm’s length property sales to represent the assessment level in your community. In any year, except the year a revaluation is implemented, the common level of assessment is the average ratio of the district in which your property is situated, and is used by the County Tax Board to determine the fairness of your assessment. Knowing the ratio is key to starting the process of determining if you have been over assessed or not.