A journal entry forces the balance without fixing what actually changed, so you're right to look deeper. The beginning balance in the reconcile window is driven by your reconciliation history, which is why your balance sheet and register can look fine while the reconcile screen is still off.
What typically causes this
- The account wasn't set up with the correct opening balance
- A previously cleared and reconciled transaction was later voided, deleted, or modified
- The company file was converted from QuickBooks Desktop for Mac or QuickBooks Online, which can leave some transactions unreconciled
- Possible data damage
Step 1: Find what changed
Run these three reports to track down the source of the discrepancy:
Reconciliation Discrepancy report: Go to Reports, then Banking, then Reconciliation Discrepancy. Select the account and select OK. This lists every transaction that changed since your last reconciliation, along with when the change was made.
Previous Reconciliation report: Go to Reports, then Banking, then Previous Reconciliation. Select the account and the most recent statement date, choose Transactions cleared at the time of reconciliation, then select Display. Compare this against your actual bank statement for that period. Note the reconciliation creation date. You'll need it for the next report.
Audit Trail report: Go to Reports, then Accountant & Taxes, then Audit Trail. Set the Account filter to the account you're reconciling. For the Date filter, leave the From field blank and set To to the statement date. For the Entered/Modified filter, set From to the reconciliation creation date you noted above and To to today. This surfaces any changes made to a transaction after it had already cleared.
It's also worth checking the Reconciliation Discrepancies account in your chart of accounts. If a past reconciliation was force-adjusted rather than properly fixed, you'll see a journal entry there.
Step 2: Fix it at the source
Once you've identified the transaction, back up your company file first, then:
- Go to Banking, then Reconcile.
- Select Undo Last Reconciliation.
- When prompted, select Continue, then OK.
- Close out of Reconcile and reopen it to redo the reconciliation with the correct beginning balance.
If the transaction causing the problem is further back, you may need to undo more than one reconciliation in sequence, working backward until the beginning balance is accurate, then redo each one in order.
If you converted from another QuickBooks product
Reconciliation works differently in QuickBooks Desktop for Mac and QuickBooks Online. If this file was converted from either one, some transactions may have gotten unreconciled during the move, which throws off the opening balance. Worth ruling out before digging further.
Let us know which report you're looking at or what the discrepancy amount is — happy to help you work through it from there.
Resources:
Fix beginning balance issues in QuickBooks Desktop
Fix issues when you're reconciling in QuickBooks Desktop