A small, persistent difference is common, but it should never be written off without an explanation. A bank reconciliation is simply a check that your bookkeeping balance, adjusted for timing items, agrees with the bank statement. If it does not, something is either missing, duplicated, entered incorrectly, or still in transit.
Start by confirming the basics. Check that you are reconciling the right account and the right statement period, and that the opening balance agrees with last month's closing balance. A wrong opening balance will carry the same difference forward every month. Then compare the statement total with your ledger total to confirm the size of the difference, rather than trying to spot it item by item at first.
Next, work through the usual causes in order. First, look for timing differences: cheques or payments you have recorded but which had not cleared by the statement date, and receipts recorded just after the cut-off. These are genuine reconciling items, not errors. Then check for bank charges, interest, direct debits, card fees and refunds that appear on the statement but have not yet been posted in your books. After that, look for duplicates, items posted to the wrong bank account, and amounts entered the wrong way round. A useful clue is that a transposition error, such as £54 entered as £45, often produces a difference divisible by nine, while a reversed receipt or payment can double the error.
Use a short monthly routine. Reconcile soon after the statement is available, tick off items in date and amount order, investigate every unmatched item before closing the month, and keep a list of outstanding items with dates so old items do not linger unnoticed. Do not force a balance with a vague adjustment. If the same difference repeats, if outstanding items are several months old, or if you suspect missing income or fraud, ask an accountant promptly, because an unreconciled balance can distort your profit, VAT and tax records.
