Skip to main content
Department of Taxation and Finance

Tax mapping in New York State

The Assessment Improvement Law (Laws of 1970, Chapter 957) required local governments to prepare and maintain tax maps in accordance with standards established by the State Board of Equalization and Assessment (currently Office of Real Property Services). For the most part, this requirement is a county responsibility; however, the cities and towns of Westchester County are required to prepare and maintain tax maps, rather than the County. This same law prescribes that the State Board shall develop rules and regulations (9 NYCRR Part 189) for the preparation and maintenance of these tax maps and assigns important duties to the municipalities in New York State related to tax map preparation and maintenance.

Perhaps the most essential of all assessment tools is an adequate tax map reflecting the size, shape and geographical characteristics of each parcel of land in the assessing unit. The tax map is a graphic display of each assessing unit's land inventory and as such is the major source to the real property assessment roll. The working copy of the tax map used by the assessor can be utilized to record and analyze property transfers, to record other features pertinent to the valuation of land and in the development of a Geographic Information System (GIS). The tax map is an invaluable tool assisting the assessor in the pursuit of real property tax equity.

When the rules for tax mapping were changed around 1970 to require a geographic address for each tax parcel, the need for a tool to manage, analyze, and display those addresses was created. The addresses take the form of a point, referenced to an actual location on the earth, that represents the visual center of each tax parcel. Many counties have opted to convert these paper tax maps to a digital environment. The process has allowed counties the use of digital property boundaries in lieu of points on the surface to further enhance the use of Geographic Information Systems. These layers, combined with the power of GIS, allows us to analyze and map the wealth of parcel level assessment information to solve problems related to: property valuation, local government reassessments, land use, environmental assessment, facility siting and economic development, public health, emergency services and disaster planning.

Local government resources