I have successfully migrated from QB Desktop to QB online. I would like to run both systems simultaneously for a few months. Can I pull in multiple times?

Which QB Desktop year version do you have?

Hey, @ccolclough-penie. 

Thanks for stopping by the Community. 

You can easily manually export information out of QuickBooks Desktop and then import it into QuickBooks Online. 

However, you won't be able to move over ALL of the data at one time, like you do the first time. 

Feel free to respond back if you have any further questions. Take care!