Hello oksana-27-hotmai,
Welcome to Community! QuickBooks Online provides the features you need, to reconcile your accounts seamlessly. However, when transactions are added, edited, or deleted after an account has been reconciled, it can have a negative impact on other areas of your books. I would be happy to provide more information, so you're on the right track with your work!
It's important to note, that modifying the reconciliation status of a transaction, will affect past and future reconciliations, as the ending balance after every reconciliation becomes the beginning balance of the following cycle. For this reason, the best course of action is to unreconcile back to the date of the transaction. An accounting professional will be able to undo the reconciliation to a specific date. If you don't have an accountant, we can help you locate a ProAdvisor in your local area.
If you have any other questions, feel free to reach back out. We would be happy to help!
