Check a whole year of bank statements at once

Why a single-statement check isn’t enough

Checking each statement on its own tells you that statement is complete. It can’t tell you that the set is complete. At year end, the problems are usually between statements: a month the client forgot to send, the same PDF downloaded twice under different names, an interim statement that repeats two weeks of transactions, or a closing balance that doesn’t carry over to the next month’s opening balance. Each one either loses transactions or counts them twice.

What the whole-year check does

1. Reads every statementEach one is converted and checked row by row, exactly as a single statement would be.
2. Puts them in date orderBy the period printed on each statement, not by file name.
3. Finds duplicates and overlapsIdentical files and repeated periods are spotted and counted once, never twice.
4. Checks the joinsEach statement’s opening balance must equal the previous statement’s closing balance. A gap in dates or balance is reported as a missing period.
5. Explains the differenceThe year’s opening balance plus money in, minus money out, is compared with the final closing balance. Any difference is broken down into what the checks found, down to £0.00 unexplained.
6. Exports one CSVEvery unique transaction, in order, with a column showing which statement it came from.

An example you can run

The converter above includes a fictional 12-month set with five problems planted in it. Choose the sample and you’ll see:

• Missing period: no statement for July. June closes at £19,513.59 but August opens at £21,674.91.
• Balance mismatch: March doesn’t add up. A payment out of £110.73 is missing from it.
• Duplicate statement: May was included twice under two file names. It is counted once.
• Overlapping period: an interim statement covering 15 November to 14 December repeats 27 transactions already in the monthly statements. They are counted once.
• Not an error: two genuine £4.80 coffees on the same day are left alone, with at most a soft note.

Opening on 1 October 2025 is £2,540.75 and closing on 30 September 2026 is £25,268.94. Adding up the 314 unique transactions leaves a difference of £2,050.59, which the check explains in full: £2,161.32 for the missing July statement, and −£110.73 for the row missing from March. Unexplained: £0.00.

Several accounts in one folder

Clients often send statements for a current account, a savings account and a credit card in one batch. The check reads the sort code, account number or account holder on each statement, separates the accounts, and checks each one on its own, so balances are never mixed.

Signs of editing

When statements come from a third party, the check also lists any that show signs of editing, such as text typed over original figures, or a PDF made in Word or an online PDF editor. See detecting edited bank statements.