Hello there, Anda.

Thank you for posting in the Community. Let me clarify how account balances work in QuickBooks.

As stated by my colleagues above, you don't need to record a Journal Entry to zero out the balances, you just have to reconcile the sub-accounts instead. 

For additional reference, you can click this article on how to Reconcile an account in QuickBooks Online.

Update me in the comments section below. I'm hoping to hear from you as soon as I can. Take care always!