Payroll Tax Engine | Symmetry

The Symmetry Tax Engine® is the gold standard in gross-to-net calculations. Perfect for building or enhancing a payroll platform. 

Whether you're a software developer creating a new solution from scratch, or a service provider looking for a way to improve your existing payroll or HCM platform, the Symmetry Tax Engine 2 is the most powerful payroll tax withholding calculator in the market.

The Symmetry Tax Engine 2 is a powerful calculator that accounts for every payroll tax imaginable, including Federal, FICA, state withholding for all 50 states, Puerto Rico, US Territories, local taxes, and various other payroll-related withholdings. Our tax engine also accounts for employer taxes, benefits taxation, and multi-state processing. Even nexus and reciprocity are considered. And because we know these taxes change frequently, our team of taxation experts and software engineers supports you with timely and accurate updates to the tax engine. The Symmetry Tax Engine 2 is the gold standard in payroll tax withholding software, and essential to your gross-to-net calculation needs.

Our payroll tax engine saves resources and research time by ensuring you get the right taxes, the first time, a vital component of any payroll process. 

The Symmetry Tax Engine 2 introduces more flexibility for implementation as well as additional features, including options for a web-hosted API or on-premise SDK. With either version you get the same great payroll tax engine, the difference is where it’s housed and who does the testing and updating.



Lightning fast. In benchmark testing, the payroll tax engine ran at an average of 1.97 milliseconds per calculation.



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



No storage of personal data. The Symmetry Tax Engine doesn’t restrict calculation sizes either, handling figures up to 15 digits.

Symmetry Tax Engine 2 FAQs

  • What is the Symmetry Tax Engine 2?

  • What is new with the Symmetry Tax Engine 2?

  • Who Needs a Tax Engine?

  • Does the Tax Engine store any personal data?

  • How is the Symmetry Tax Engine 2 updated?

  • Does the Symmetry Tax Engine 2 take nexus and reciprocity into account?

  • How accurate are the Symmetry Tax Engine 2 location codes?

  • How is the Symmetry Tax Engine 2 installed?

  • The Tax Engine is great. What other Symmetry Software products can help me?

  • What companies use the Symmetry Tax Engine?

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.