What is geocoding?
Geocoding is the computational process of transforming a physical address into a precise location on the Earth’s surface, most notably a pair of latitude and longitude coordinates.
Geocoding is useful for a myriad of different applications, and especially important in payroll for determining the precise taxes that apply to individual employees. Geocoding allows employers to quickly access important data pertaining to an employee’s home and work addresses such as the taxes that apply.
Geocoding relies on a digital representation of an address, as well as maps of roads and other boundaries. Spatial data made possible by geographical interface system (GIS) mapping is also utilized in the geocoding process.
In the payroll world, stacking GIS map layers allows Symmetry to pinpoint all the taxes and withholding forms that apply to a set of latitude and longitude coordinates. Symmetry then combines the GIS mapping with data from the Symmetry Tax Engine and Symmetry Payroll Forms to produce the most accurate results. For example, as illustrated below, the basemap shows a typical geographic map such as one you would find on Google or Bing maps.
Symmetry then places a variety of shapefiles representing the states and territories, all counties, necessary school districts, cities, and other unique taxing jurisdictions on top of the basemap to validate specific areas. For example, before Symmetry can make a payroll calculation, we check what geographic shapes contain coordinates generated from home and work address combinations. Once we have identified what areas the addresses are in, our software then applies special rules for reciprocity and nexus along with tax laws to determine the applicable taxes and withholding forms. Finally, based on this information we can calculate.