Troubleshooting

Unmatched lines on a supplier statement: the six usual causes

Two files, thirty lines each, and four of them won't pair up. Before you start adjusting anything, identify which of the six situations you are actually in — because each has a different fix, a different piece of evidence to request, and a different owner. Adjusting the ledger for something that merely needs waiting is how books quietly drift.

1. A bill you never entered

Signs: a line on the supplier's statement with no counterpart in your books, usually with a reference you don't recognise and often for a delivery you did receive.

What to do: get the document before you post anything. Ask the supplier for a copy of the invoice PDF — do not enter it from the statement line alone, because the statement typically omits line detail, VAT codes, and the nominal account. Enter it once the document arrives, exactly as invoiced.

This is the case worth preventing: set a rule that any delivery note without a matching invoice is chased weekly, not monthly.

2. A payment in transit

Signs: the payment is in your books but missing from their statement, and the difference roughly equals a payment run you made near the statement date. The closing balances differ by that amount and everything else matches.

What to do: check whether the payment actually left — reconciled date, clearing date, and whether it bounced. If it is simply in flight, do nothing to the ledger; note it as a timing difference and confirm it appears on next month's statement. Ask for the remittance advice if they claim never to have received it.

3. An unapplied credit note

Signs: they show a credit note; you have none, or you have it sitting unallocated against the wrong bill. Totals differ by the credit amount, often for goods returned weeks ago.

What to do: request the credit note number and date, enter it against the original bill, and then allocate it. Unapplied credits are the most common reason an Aged Payables report overstates what you owe — see Aged Payables vs a supplier statement for why the two views diverge here.

4. An amount mismatch on the same reference

Signs: same invoice number on both sides, different amounts. Usually small — a delivery charge, a price change, a partial credit applied to the same invoice number.

What to do: this is the one case where one side is simply wrong, and you need the invoice and the delivery note side by side to find out which. The difference usually corresponds to something physical: quantity short delivered, a restocking fee, VAT applied at the wrong rate. Do not average it out — find the cause, because it tends to recur with the same supplier.

5. Timing and cut-off differences

Signs: the mismatched lines cluster at the very start or end of the statement period, and the references do appear — just on the wrong side of the boundary.

What to do: reconcile to the same cut-off date on both sides. Most tool-supported workflows, including the ones described in the reconciliation walkthrough, handle this by matching on date windows rather than exact dates. If the difference disappears when you extend the window, it was never a difference.

6. Duplicate or double-posted entries

Signs: everything matches except two identical references on one side, often with the same amount and date — or a bill that was paid twice and shows once.

What to do: check whether the same invoice was entered twice under slightly different references (a leading zero, a transposed character). This is the ugliest of the six because it is your error rather than a timing issue, and the only real fix is reversing the duplicate and recording why.

Five habits that stop this recurring

• Reconcile monthly, not quarterly — differences are easier to explain while people remember.
• Never enter a bill from a statement line; always get the invoice.
• Keep remittance advice for every payment run; it settles most "you never paid" disputes in one email.
• Write the reason next to every adjustment you make, in the reference field if nowhere else.
• Watch for supplier-shaped patterns: if one supplier accounts for most of your unmatched lines, the problem is theirs, not your process.

Getting the six cases listed automatically

The diagnosis is the slow part; the comparison itself is mechanical. Statemint reads both files in your browser, pairs them, sorts the leftovers into exactly these categories, and lets you export a follow-up CSV where each unmatched line carries the next action — request the invoice, chase the payment, apply the credit. It takes about a minute, and because nothing is uploaded, you can do it with client data you would otherwise have to think twice about.

Try it with your own files — free preview, no account, no upload.