Hi @AlisonHammersley (Pat McCarthy),
Welcome to the Intuit Community and thank you for reaching out to us here. QuickBooks is a flexible program that helps you to manage your accounting with ease. I'll be glad to share some information on migrating historical payroll data so you're on the right track with your work.
When transitioning from QuickBooks Desktop to QuickBooks Online, only the employees basic information (name, gender, birth date, etc.) will migrate over, but their historical payroll does not. When you migrate from Desktop to Online, and you choose to enable or subscribe to our Online Payroll as well, you'll need to go through the 'Payroll Setup' within your account prior to running your first payroll. The payroll setup will walk you through entering/reviewing the employees pay types, setting up tax rates, and entering the year-to-date historical payroll totals for each employee, as well as the quarter-to-date totals for each employee. These historical payroll totals can be gathered by running your Payroll Details Report in your older QuickBooks Desktop version.
The payroll setup is designed to allow you to add in this information at your convinience, and save as you go, so whenever you're ready to get started, you can access the QBO Payroll setup tasks by:
1. Going to the 'Payroll' tab from your left panel
2. Select 'Overview'
3. Then you can choose 'Start' on the set up task you want to work on
Once you have the basics entered in the set up, you can use this article: https://quickbooks.intuit.com/learn-support/en-ca/help-article/payroll-setup/add-pay-history-quickbo... to walk you through adding in the historical payroll totals. This will also explain how QuickBooks uses these totals to calculate the taxes and totals on your future payrolls.
With all of that being said, once you've finished the payroll setup, there's a possibility that you may see some under-payments or over-payments in taxes from your Payroll Tax section. If you do, this is due to the tax rates and totals having not been entered in the payroll setup prior to you running payroll in your QuickBooks Online account. However, we can walk you through getting those fixed if that does happen to be the case. Just reach out to us through the 'Help (?)' icon in account, then choose 'Contact Us', and from there you'll have the option to chat in or schedule a call-back and we can get you taken care of.
I hope this helps clarify the process a bit, and we're here for you if you need anything else.
