You can exclude transactions if you don't need them. Doing so will stop QuickBooks Self-Employed (QBSE) from including any income or expense transactions from your tax year calculations in the Home or Expense screens.
To exclude transactions, here's what you'll need to do:
In the left menu, click Transactions.
Filter the Date to Last year.
Click the box beside the DATE column to select all transactions.
Choose Exclude, then hit the Apply button.
To learn more about excluding transactions in QBSE, you can refer below articles:
Are you trying to delete a downloaded transaction via a bank connection? If so, we're unable to delete a transaction that was downloaded through a bank connection. However, we can exclude them. You may follow the steps provided by my colleague on how exclude them in QuickBooks.
I would also encourage you checking out these articles for more details about excluding transactions in QBSE: