How to check that a converted bank statement reconciles

A converted statement that "looks right" is worth very little; statements are tables of near-identical rows, and the eye cannot audit them. Arithmetic can. A statement carries enough internal redundancy to prove its own completeness, which is what reconciliation does.

The three checks

1. The summary equation

Opening balance + total money in − total money out = closing balance.

Every UK statement prints an opening and closing balance (sometimes as brought forward and carried forward rows). If the equation does not hold to the penny, at least one row is missing, duplicated, or has a wrong amount or direction. This one check catches most conversion failures, but it cannot tell you which row is wrong, and two errors can cancel each other out.

2. Running-balance transitions

For each row that prints a running balance: previous balance + this row's signed amount = this row's balance.

This is the precise version of check one. It localises an error to the exact row where the chain first breaks. Some layouts (NatWest, for example) print a balance only on the last transaction of each day; in that case accumulate the day's amounts and check the day-end figure. If the transitions all hold, it is very hard for a missing or wrong row to hide.

3. Direction consistency

Money out rows must carry negative signed amounts, money in rows positive, and no row should have both. Column-drift errors, where a debit lands in the credit column, pass a naive sum check twice over but fail this one against the running balances.

Doing it in a spreadsheet

With columns Date, Description, Out, In, Balance starting at row 2:

=ROUND(E2 + D3 - C3, 2) = E3

filled down, flags the first broken transition. Then compare =E2 + SUM(D3:D999) - SUM(C3:C999) with the printed closing balance.

The free statement balance checker does the same locally on pasted rows or a CSV and reports the first break; the converter runs all three checks automatically and labels the result verified only when they pass.

When it does not reconcile

Do not force it. Find the first broken transition, compare that row with the PDF, and correct the actual error. A statement massaged until the totals happen to match is worse than one honestly labelled unreconciled, because it looks trustworthy and is not.

Reviewed 15 July 2026.