Ask your third-party payroll processor to provide a flat file type such as Excel, csv, or txt.
Import the flat file into QuickBooks as a Journal Entry using Transaction Pro Importer.
It's that easy.
"During our most recent health checkup ... we were informed that on occasion IIF files can be the cause of file corruption and if possible, avoiding them is a good thing. Doing some homework we found you can download .xls files from our payroll provider and use Transaction Pro to do the import. We took it for a spin and found it worked as intended. Understanding the program, setting it up to work with our file and running the program took about 20 minutes the first time. After the initial import, if you saved your setup, you can simply click through the next import and it will only take about 2-5 minutes. Highly recommend if your workflow is similar to ours."
-Daniel, Transaction Pro User