Appreciate you for getting back to us, @AvonDM.

QuickBooks Online can also handle a large number of transactions. We can't tell if the targets generated in the last 12 months are for a small or medium-sized company. As long as it's exceeding the minimum data size capability, QuickBooks Online is no longer recommended for you. If that's the case, you can remain using your current product.

Still, I recommend following the suggestion shared by my colleagues above. Also, you can check out this article for more details about moving data from QuickBooks Desktop (QBDT) to QuickBooks Online (QBO): Learn how features and data move from QBDT to QBO. 

In case you're looking for more tips and information about QuickBooks Desktop, you can utilize this article: QuickBooks Desktop Help Articles.

We'll be around if you have a follow-up question about this matter or have any other QuickBooks concerns. Take care, AvonDM.