The Community team and I are happy to hear that you're considering migrating to QuickBooks Online (QBO), @LizIrish86. I can outline the necessary information to answer all your questions.
First, when you convert your data from QuickBooks Desktop Pro 2020 to QuickBooks Online, the majority of your data will transfer over. Please be aware that not everything will transfer seamlessly due to differences in features between the versions. Yes, you can still refer back to your Desktop version and run reports or look at historical data after you migrate to QBO.
Second, yes, each company requires its own subscription. There isn't a way to manage two separate companies under a single subscription with completely segregated data. Regarding classes, this feature allows you to classify transactions within the same company. This offers you the benefit of gaining a clearer understanding of your sales, expenses, or profitability by business segments.
In addition, please read this article: Learn how features and data move from QuickBooks Desktop to QuickBooks Online. This article covers various topics regarding the movement of data. Please refer directly to 'Features that move and don't move over to QuickBooks Online'. You can also explore the other topics for a more comprehensive understanding.
Please check the articles below for more references:
Lastly, for a good reference on handling your QuickBooks data, you may want to read this article: Fix errors when you move from QuickBooks Desktop to QuickBooks Online.
Helping you is our primary goal. Should any questions arise, please respond through this thread. Wishing you a successful migration journey!
