Correct an error on the side that contains it. A confirmed unrelated bank charge wrongly lowers the statement balance, so add it back on the bank side and request a bank correction; do not copy it into correct books. If an expense payment was entered too large, the books reduced Cash too much. Restore only the excess with a debit to Cash and a credit to the same expense.
Worked example
Separate contrast example: a payment of 70 entered as 40 leaves book Cash too high by 30, so subtract 30. Bank 300 + deposit 30 - check 20 = 310; books 344 - fee 4 - correction 30 = 310. Your case below has the opposite book-error direction: inspect its evidence.
Fictional design club / same closing date
All amounts are fictional dollars. Statement balance: 500; book Cash: 481. The bank confirms it wrongly deducted another customer's 20-dollar charge. Deposit in transit: 45; outstanding check: 55. Interest 4 and fee 5 are missing from the books. A separate repair payment cleared correctly for 36, but the books debited Repair Expense and credited Cash for 66. Its receipt confirms 36. These are all differences.