What adjustment is needed when a check that was written in a previous month appears on the current month's bank statement?
A check written in any previous month but not appearing on previous bank statements, should have been included in last month's list of outstanding checks. Now that the check appears on the current month's bank statement, the check should not be included in the current month's list of outstanding checks. No other action is needed.
The general ledger account has always been correct, because the amount of the check reduced the general ledger account balance at the time the check was written and recorded.
The problem was the previous bank statements. The bank statement balances were too high since the check had not yet cleared the bank checking account. That's why we subtract the amount of the outstanding checks from the bank statement balance. Now that the bank statement balance has been reduced by the check clearing the bank account, there is no longer a need to further subtract the amount of the check as outstanding.