Paychex Payroll to QuickBooks Desktop: IIF Journal Entry Guide

Paychex Flex offers a QuickBooks Desktop integration, but it often requires account mapping review and adjustment. For bookkeepers who want clean, reliable IIF output every pay run, PostBooks provides full control: map your Paychex accounts to QB Desktop once and generate a correct IIF file automatically each period.

How PostBooks connects Paychex to QuickBooks Desktop

  1. Download the Paychex payroll summary or GL report. Export from Paychex Flex > Reports > Payroll Summary as CSV.
  2. Upload to PostBooks and map accounts. PostBooks maps Paychex line items to your QuickBooks Desktop chart of accounts. Save the mapping and reuse it every pay run.
  3. Export as IIF file. PostBooks generates a valid IIF file ready to import into QuickBooks Desktop via File > Utilities > Import > IIF Files.

Frequently Asked Questions

Paychex Flex has a QuickBooks Desktop integration, but the output sometimes needs manual review. PostBooks gives you precise control: map Paychex accounts to QB Desktop once and get a clean IIF file every pay run.
Export the Paychex payroll summary as CSV, upload it to PostBooks, and PostBooks generates the IIF file ready for import into QuickBooks Desktop via File > Utilities > Import > IIF Files.

Stop entering Paychex payroll manually

PostBooks converts your Paychex reports into balanced journal entries ready to import into QuickBooks Desktop — in under 60 seconds.

Try PostBooks free for 14 days