Symmetry Tax Engine

Your most complicated payroll tax calculations don't stand a chance. 

Whether you're a software developer starting from scratch, or a payroll service provider planning on improving your existing payroll solution, the Symmetry Tax Engine is the most powerful tax engine on the market.

A tax engine is a powerful calculator that calculates every payroll tax imaginable, including Federal, FICA, state withholdings for all 50 states, Puerto Rico, US Territories, local taxes, and various other payroll-related withholdings. Our tax engine accounts for employer taxes, benefits taxation, and multi-state processing. Even nexus and reciprocity are considered. And because we know these taxes change frequently, we support you with timely and accurate updates to the engine. 

But the best part? Knowing your payroll taxes will be right, the first time.

Symmetry Tax Engine



Quick calculations, monthly updates - the tax engine helps you make sure your payroll is accurate, every time.



Utilizes geocoding technology to normalize addresses, and also takes nexus, reciprocity, state, local, and federal taxes into consideration.



Consistently updated to always calculate the right taxes, the first time. The tax engine just works - calculating even the most complicated tax scenarios.

Symmetry Tax Engine FAQs

Have you already built a payroll application? How do you stay current?

If you've ever wondered if a better method to stay on top of withholding tax changes existed, wonder no longer. With the Tax Notification Service, you'll be up to date with recent payroll withholding and tax changes and connected directly to the supporting documentation. 

Once logged in, all tax changes for the current year are presented in alphabetical order by state. You can look for specific tax changes over time by selecting any of the tax categories, or by clicking the name of the state you are researching. You can also view tax changes by year and Symmetry Tax Engine release number. Documentation from the state regarding each change is included, when available, as well. That means no more excess time spent plowing through pages of rates on federal and state websites.