The Payroll API provides all the capabilities needed to integrate pay data with Paychex Flex.  It exposes resources for Pay Components, Pay Periods and Checks. You will be using these end points, in combination with foundational APIs to create your solution.  Please refer to the Quick Start guide to get an understanding of the core functionality of the Paychex API.  

This will allow solutions to send and work with unprocessed check information.  The most common use cases for this are adding hours worked and commission/bonus/tip amounts to checks in Flex payroll entry. While an API solution can be used to send payroll data, the client or Paychex service provider must still review and complete the submission of the payroll for processing.

If you are interested in the Payroll API, please contact your Paychex sales rep, service provider, or use the contact us link on this website.

Pay Periods

The company pay period calendar enables syncing and ensuring wages are paid on the correct dates.  Pay periods are typically used for applying earnings and deductions that a worker accumulated within the pay period range that can be added into one or more checks. The API supports the use of pay periods that are unprocessed. A pay period is used for creating and retrieving unprocessed checks.

Pay Components

Companies can define the pay components that are applicable to their business and are used in constructing a workers check. The pay components are put into classifications and can have different effects on the outcome of the check. The company can set when these pay components are available by defining start and end dates, these dates come into play when creating a check in conjunction with the pay periods date range.  The API will allow you to pull back all of the Pay Components that the company has.  When dealing with checks (creation and retrieval) the API currently will only allow the Pay Components that are non-deductions on checks.


The API will allow you to work with earnings on unprocessed checks. Using the other resources like workers, pay period, and pay components you have the ability to POST, GET, and DELETE earnings for unprocessed checks. When creating checks you have the ability to define for a worker their earnings using the pay components and combination of rate/amounts. When predefined configurations like reoccurring earnings and deductions are set on a worker these will automatically be applied to the check when it is created from the API.