Backup data (see end of Help Article)
Get a report that shows the exact transaction that was reconciled incorrectly. To get this report, go to Other Reports, Journal Reports.
Select the Journal Type of the incorrect transaction. If you wrote an AP check, you will select AP, if you made a check adjustment from within the Bank Rec, you will select CB.
Print the report so you have it when you make your adjusting entry.
Go into your Bank Reconciliation and enter the same information you did when you last reconciled. The ending balance should match the beginning balance shown, and the date should be the closing statement date of the reconciliation you just completed.
Mark the check you should have marked when you reconciled last time. This will make the Difference the same as the check amount. Now you must make an adjusting entry. At the top right corner of the Rec window, click the Add Chk/Adj button.
You will be prompted to enter the Debit side of the entry. Whatever you enter will automatically credit the checking account and debit the expense account. Because you are making an entry to REVERSE a check, you must use a negative number in amount to record the information correctly.
Now the Difference in your bank rec will equal zero, and you may complete the reconciliation.
If the check you had incorrectly marked is a real check that will need to be marked in a future bank reconciliation, you must re-create that check. You may not re-use the same check number, however, so you must use a prefix such as 1000### where the ### is the original check number. That will make it easier to match on the Bank Reconciliation.
Please note: if at any time you make a mistake in this reversal process, exit out of the bank reconciliation and Restore the data you just backed up.
BACKUP: Let it go to the default directory—just hit the next key all the way through and process
RESTORE: Let it use the default directory, just hit the next key all the way through and process