I can help you with this, 1 Learning.

You can reconcile your past transactions one year at a time. This way, all adjustments, service fees, and interest you enter during the reconciliation process will apply to the year in which those transactions occurred. It would also be best to consult with your accountant so you'd be advised of the best method for you to reconcile statements and transactions for multiple years. 

I'll show you how:

1. Go to the Banking menu and select Reconcile.
2. Select the Account drop-down then choose the account you want to reconcile.
3. In the Statement Date field, choose the date from the financial statement you selected.
4. In the Ending Balance field, enter the ending balance from your statement.
5. Compare the amount shown in the Beginning Balance field with the opening balance on the oldest statement you need to reconcile.
6. Enter the total Service Charge and Interest Earned.
7. Follow the screen transaction to complete the process.

You can check this article for more detailed steps: Reconcile an account for multiple months or years of transactions and financial statements.

Also, you can check our Year-end checklist in QBDT. This will guide you through the process of completing your task in QuickBooks so you can close your previous year and prepare for the upcoming one. 

Keep me posted if you have other questions about reconciling your account. I'm always here to help.