I understand that you want to change transfer into an expense in QuickBooks Online (QBO), GCurry. Let's get into the details about this.

It is important to note that changing transfer into an expense isn't possible in QuickBooks Online (QBO). Moreover, when managing both business and personal accounts, maintaining strict transaction separation is critical to ensure accurate financial records and prevent accounting complications.

After you undo the transaction, exclude it by clicking on the transaction to expand the details and then hitting Exclude button. Next, locate the expense transaction found in your chart of accounts and manually mark it as cleared by using the C to ensure that your financial records remain accurate.

You can check out these screenshots for visual reference:

Moreover, for detailed information and steps in excluding bank transactions, you can visit this article for reference: Exclude a bank transaction you downloaded into QuickBooks Online.

Additionally, for your future reference in case you want to reconcile your accounts, you can check out this article for guidance: Reconcile an account in QuickBooks Online.

Keep us posted if you have other concerns about categorizing your transactions and managing transfers in QuickBooks Online. We're always here to help 24/7.