How many times I can undo my reconciliation?

I'm glad to provide you with the answer to your concern, Erika. 

It has no limitations in undoing a reconciliation in the QuickBooks Online (QBO) account. But we don't have an option to undo the whole reconciliation. We can only do them manually. 

Here's how: 

1. Go to Settings ⚙, then Chart of accounts.
2. Find the account that has the reconciled transaction. Then select View register.
3. Look for the transaction. If marked R in the checkmark ✔ column.
4. Select the transaction to expand the view.
5. In the checkmark ✔ column, select the box with the “R” until the box is blank. It will remove the transaction from the reconciliation.
6. Select Save.

However, if your accountant has a QuickBooks Online Accountant account, they can undo the entire reconciliation on your behalf. By this, you'll permit your accountant to access your QBO. This way, they'll undo the whole reconciliation. 

In addition, you'll want to check this article and learn how to run reports in QuickBooks Online: Run reports in QuickBooks Online. 

Please don't hesitate to go back to this thread should you need additional assistance managing reconciliation in QuickBooks Online. Stay safe.