There isn’t a way because the two should be kept separate for legal reasons too.
However, you can have your contacts, clients and suppliers copied over (either manually via the back up and import options, or by asking the QF team nicely!)
Some notes about the differences etc can be seen here:
What I would suggest you do, is either set up a secondary email address for the new account (or set the existing account to that one to free up your main one for the new account).
Hope that helps