Hi there jbaldwin,
Undoing reconciliations is one of the awesome features that is available exclusively for those who use QuickBooks Online Accountant. Sometimes when there are transactions that need editing, it's easier to undo the entire reconciliation and start over with a blank slate. If you're using QuickBooks Online Accountant and need to undo a client's reconciliation, I'll show you how.
There are a few things to consider before deleting reconciliations. The first is that you'll want to download attachments that are tied to your reconciliations, because once undone, the attachments will be deleted. You'll also want to be sure to delete the most recent reconciliation and work backwards to avoid errors. There is no special password required for undoing the reconciliation, you just need to follow the steps below:
The article below outlines the steps I've described above and also includes some additional information that'll be helpful to review:
There are loads of special tools and features available exclusively for accountant users in QuickBooks Online Accountant. I know that you or your accountant will make great use of them! Best of luck.