Launched publicly in December 2012, ZenPayroll says it is processing more than $400 million in annual payroll. The company charges $25 plus $5 per person for the first 10 employees and $2 per person for each additional person. Zen offers what it calls delightful payroll for $29 per month, including direct deposit, unlimited payroll runs, year-end W-2s and 1099s, and new hire reporting for both employees and contractors.

The company was co-founded by CEO Joshua Reeves and CTO Edward Kim. Reeves was the CEO and co-founder of Unwrap, a SaaS start-up acquired in 2010. Zen describes its goal as "to re-imagine payroll for the modern business." It raised $6.1 million in seed funds in April 2012 from the CEOs of Yelp, Box, Dropbox, Yammer and others, as well as from Google Ventures and Salesforce

In January, Zen partnered with FreshBooks to integrate the products so that payroll expenses automatically show up in FreshBooks each time payroll is run with payroll adjustments and cancellations reflected in FreshBooks as well.