Geocoding and Symmetry

Symmetry Tax Engine

The two main concepts at work in the Symmetry Tax Engine (STE) that provide accurate withholding are the Symmetry Location Service and Unique Tax IDs. The Symmetry Location Service uses geolocation to determine precise employee work and home address locations. When paired with Unique Tax IDs, the Symmetry Tax Engine returns to clients’ applications the exact taxes that apply to each individual.

Here’s how it works:

1. Enter the employees’ home and work addresses in the STE.

2. Symmetry determines the latitude and longitude of employees’ home and work addresses, normalizing the addresses in the process.

3. Symmetry then places these locations within tax jurisdiction boundary shapefiles. Our constantly updated library contains over 35,000 geospatial files.

4. Symmetry applies reciprocity and nexus settings.

5. Symmetry Location Service returns to your application location codes, IDs, coordinates, and accuracy values, which can be added to the employee record for calculating payroll taxes.

Symmetry Payroll Forms

Symmetry Payroll Forms (SPF) uses geolocation as part of its process for determining what withholding forms apply to each individual employee.

As employees start the Guide Me process of Symmetry Payroll Forms, they input their home address on their Form W-4. The employee work address is set at the company level in the Symmetry Payroll Forms Settings Builder by your administrator. For clients who pass their employee data into Symmetry Payroll Forms via JSON, home and work addresses are set through the JSON data input. Once SPF has the home and work address of each employee, the Symmetry Payroll Forms web service calls Symmetry’s servers to perform the geolocation, returning the appropriate forms.

Symmetry also uses geolocation to pre-populate the forms with local tax information such as Political Subdivision (PSD) codes and school districts for Pennsylvania forms. In this scenario, the geocoded addresses together with the Symmetry Payroll Point web service return the local tax information so that employees and employers don’t have to perform manual lookups themselves.

Symmetry Payroll Point

Symmetry Payroll Point uses geolocation to determine the latitude and longitude of home and work addresses before querying our collection of shapefiles to retrieve the GNIS codes, which map to the Symmetry Tax Engine. As part of this process, Symmetry pulls the metadata associated with those addresses such as the state, county, GNIS number, city GNIS number, and Symmetry Tax Engine code type—whether school district, jurisdiction, etc. With this meta information, Symmetry then retrieves the geom or polygon, which is the shape of the shapefile and verifies whether or not the addresses are in a tax boundary. If they are, Symmetry returns the taxes that apply and the minimum wage rates.

Symmetry’s library of shapefiles come from a variety of sources. The U.S. Census Bureau along with the GIS departments of the 50 State Departments of Transportation provide a large quantity of the shapefiles. Symmetry also creates its own custom library of Ohio JEDDs, Kentucky TIFs to DAFs, and more, to round out our collection.

Calculators by Symmetry

Similar to Symmetry Payroll Point, Calculators by Symmetry relies on user-inputted data for the home and work addresses in order to calculate the proper taxes that apply. For states that have local taxes, work address fields and resident and nonresident buttons appear whereby the user can input a work address, which is then geocoded to determine the proper taxes. Leaving these address fields blank will result in no city or school district tax being calculated, and will thus not provide as accurate withholding results for the user.