@beachfarmer 

Sign in as an admin to the desktop company file you want to move.
On your keyboard, press Ctrl + 1 to open the Product Information window.
Press Ctrl + B + Q, then select OK to display the export window.
On the export window, select Get started.
Sign in as an admin to your QuickBooks Online company.

https://quickbooks.grsm.io/US

https://quickbooks.grsm.io/us-promo

Select Choose online company, then select the QuickBooks Online company you want to replace with your company file.
Select Continue.
If you track inventory in QuickBooks Desktop:
Select Yes to bring them over, then specify the as of date.
Select No if you want to set up new items later in QuickBooks Online.
Enter “Agree” in the text field, then select Replace.
Select Yes, go ahead and replace the data, then select Replace.

Keep in mind, you won't be able to migrate some types of data (e.g attachments, estimates, purchase orders, jobs, sales reps, custom fields). You may consider to purchase a 3rd party conversion service to do so.