If my Owner paid a supplier from his personal bank account. How do I record it in QBS noting that the expense was already recorded to the mentioned supplier

Hello there, @accounting-kamka. Let me share the steps and information recording transactions in QuickBooks Online (QBO).

When recording business expenses in QBO that have been paid from a personal bank account, instead of creating an expense, I suggest creating a Journal Entry. This way, you can properly record the business expenses using personal funds.

But first, be sure to delete the expense that was already recorded to avoid doubling the expense in your reports, take note of the details, and then follow these steps to create the journal entry:

1. Sign in to your QuickBooks Online account.
2. Under the OTHER column, select Journal Entry.
3. In the Account field, click the drop-down arrow, then choose an expense account or select + Add new to add a new expense account.
4. Enter the purchase amount in the Debits column.
5. On the second line, select Partner's equity or Owner's equity or click + Add new to add a new bank account 
6. Enter the same purchase amount in the Credits column.
7. Click Save and close.

Once the owner decides to reimburse their money for business expenses, you can either record an Expense if the owner's payment method is a credit card or record a Check for ACH, online payments, or check transactions. If you also want to record reimbursement options, you can refer to this article: Pay for business expenses with personal funds.

Additionally, you can check this article to learn how to run basic financial reports in QBO: Run reports in QuickBooks Online.

You can visit us back in the comment section if you have other concerns about adding a personal bank account or creating a journal entry in QBO. we're always here to lend a hand. Keep safe.