Hello there, @info872.
You can enter Prior Payroll information into QuickBooks Online (QBO) yourself as long as:
For more information about the process, consider checking out this article: enter year to date figures.
If you need anything else, please don't hesitate to drop a comment below.
As another option, you may create JE to record historical payroll data. Utilize the trial period of this 3rd party tool to import JE in bulk.
Should you need to purchase it, use promo code 20PERCENTOFF at checkout, valid until April 30th, 2020