I'll provide more information about your unbalanced balance sheet report in QuickBooks Online (QBO), Simon.
When a new fiscal year starts, QBO automatically adds the net income from the previous fiscal year to your Balance Sheet as Retained Earnings. Your Retained Earnings show the total of your company's income and expenses from all previous years.
Let's run the balance sheet report to see the previous year's balance:
Go Reports menu.
Type Balance Sheet in the search bar.
From the Report period, choose This Fiscal Year-to-date from the dropdown arrow.
Click Run report.
From there, you can locate the previous year's balance in the Retained Earnings section.
It's best to consult with your accountant to ensure that can help verify that your books are accurate.