Thank you for adding a post here in the Community forum, @bisi-hristova.
Allow me to share information about reconciling accounts in QuickBooks Online (QBO).
If you don't start your reconciliation from the oldest transaction it'll cause issues and what happens is, your bank balance will not match to the current balance. That said, you need to finish the 2018 reconciliation first, before proceeding to 2019. If you don't want to reconcile the 2018 transactions, then you have to delete those so you can reconcile 2019.
Also, reconciliation ca be balance by creating a 2019 Jan1 opening balance and manually reconcile in the bank register. But, the bank register won't match your bank statement balance in results to confusion in the future.
Lastly, you can read the topics from these articles to learn more about how to enter an opening balance in QBO:
You can also know more about reconciliation by checking out the details from these links:
Feel free to add a comment below if you have any other questions. I'm always here to help. Have a good day!
