Why would the Bank Balance be different than the Register Balance after a successful Reconciliation?

Thanks for posting in the Community, @SCondon. I'll share information on why Bank Balance is different from the Register Balance after a reconciliation.

There are several factors that cause the difference. You can check the lists below:

• There's an outstanding transaction.
• New upload transaction to the connected account after the reconciliation.
• Edited or deleted transactions.
• Credit card (liability) account. 

To fix this, I recommend matching and categorizing all your downloaded transactions and making all the necessary corrections to your entries. You can use your bank statement as a reference when performing these procedures. For the complete guide, please see this article: Fix issues for accounts you've reconciled in the past in QuickBooks Online.

You can also check the Audit log section to see if someone made changes before and after the reconciliation that caused the difference in balance. Here's how:

1. Select Audit log from the Settings tab.
2. Click the Filter tab.
3. Choose the correct User, Date, or Events filter to narrow the results.
4. Then, click Apply.

Check out this article for more information: Use the audit log in QuickBooks Online.

Also, to correct the reconciled period, you can undo the reconciliation process. For more insights, you can use this article: Undo and remove transactions from reconciliations in QuickBooks Online.

I'll also share this article  to learn how  to delete or void the transactions added: Void or delete transactions in QuickBooks Online.

I'm all ears if you have other concerns about managing your Bank and Register balance in QBO. You can drop a comment below, and I'll gladly help. Take care, and have a good one.