Last updated November 6, 2026
Invoice reconciliation means matching each invoice you've issued to the money received for it, so that every balance on your books is really unpaid. A service firm has a second check too: that all the work delivered got invoiced. Do both monthly, working from the bank statement rather than from memory.
What does invoice reconciliation mean for a service firm?
Invoice reconciliation for a service firm is two separate checks. The first runs from invoices to the bank: was each one paid, and do your records say so? The second runs from the work to the invoices: did everything you delivered get billed?
The second check is the one a firm selling goods doesn't need in the same way. Stock leaves a warehouse and leaves a record behind it. An extra afternoon's work or a stage that finished quietly leaves nothing, and nobody will ring to remind you. You may also see "three-way matching" of purchase orders, deliveries and supplier invoices, which is a purchasing control and a different job.
How do you reconcile invoices to the bank?
You reconcile invoices to the bank by working through the statement line by line, then proving the total. Set aside an hour at month-end and follow this order.
- Mark every customer receipt on the bank statement. Leave out payments out and transfers between your own accounts.
- Match each receipt to an invoice by reference, then amount, then customer name.
- Enter anything not yet recorded, using the date on the statement.
- List what's left over. Receipts you can't place go on a list of their own, and they don't go against the nearest likely invoice.
- Work out what should still be owed, as in the example below.
- List the open balances and add them up. The two figures should agree.
- Find any difference and write down what it was. Then chase the customers who really do owe you.
Do this before you send reminders. Chasing someone for an invoice they paid three weeks ago costs more goodwill than the delay was worth.
A worked month-end reconciliation
A month-end reconciliation compares what should be owed with what your open invoices say is owed. Here's an invented example for October. Use figures including VAT throughout, because that's what customers pay.
| What should be owed | Amount |
|---|---|
| Owed at 1 October | €14,200.00 |
| Add invoices issued in October | €9,600.00 |
| Less receipts from customers | −€11,350.00 |
| Less invoices voided or credited | −€480.00 |
| Should be owed at 31 October | €11,970.00 |
| What your open invoices say | Balance |
|---|---|
| INV-2026-0071 | €2,400.00 |
| INV-2026-0088, part paid | €1,000.00 |
| INV-2026-0093 | €3,120.00 |
| INV-2026-0104 | €1,560.00 |
| INV-2026-0117 | €3,890.00 |
| Total open | €11,970.00 |
The two totals agree, so the month is reconciled. Save a copy with the date on it, because next month's first line is this month's last.
How do you find a reconciliation difference?
A reconciliation difference usually gives away its own cause, so look at its size before you look at anything else.
| The difference is | It usually means |
|---|---|
| The exact amount of one invoice | An invoice or a payment is missing, or was entered twice |
| Double the amount of a payment | A payment was added where it should have been deducted |
| Divisible by 9 | Two digits were swapped: €1,520 typed as €1,250 leaves €270 |
| A few euros | A bank charge, rounding, or an exchange rate |
| Round and unexplained | A customer's payment on account, sitting against no invoice |
Why don't payments match invoices?
Payments fail to match invoices for a handful of ordinary reasons, and each has a settled fix.
| What you see at the bank | The likely cause | What to do |
|---|---|---|
| A few euros short | The sender's bank took a charge | Absorb it or ask for it, then record what's decided |
| One sum, several invoices | The customer paid a batch | Ask for the remittance, split it across the invoices |
| No reference at all | Their accounts system omitted it | Look for the same amount, check the sender, then ask |
| More than the invoice | Two invoices paid, or a duplicate | Check, then hold as a credit or refund it |
| Less than the invoice, by a round percentage | Withholding tax on a cross-border payment | Ask for the tax certificate, and ask your accountant |
| A foreign-currency amount that doesn't quite fit | Exchange rate on the day | Record what arrived, and see foreign-currency invoices |
Part payments have their own guide.
How do you check that all your work was invoiced?
You check that all work was invoiced by starting from a list of the work, not a list of invoices. Invoices can't show you what's missing from them. Go through these once a month:
- Accepted quotes: the invoices made from each should add up to the quote, or to the stages billed so far.
- Stage payments: any stage that finished this month should have an invoice dated this month.
- Retainers: one invoice per client, per period. A monthly retainer that was paused and never restarted is easy to miss.
- Extra work: anything agreed by email during a job.
- Costs to re-bill: check your expenses for anything you meant to pass on.
Anything you find goes on a WIP report or straight onto an invoice. Doing this the month after the work is far easier than three months later, when the client has already closed their budget.
Reconciling invoices in ERPFlow
ERPFlow has no bank feed, no bank statement import and no payment matching. You read the statement and enter each receipt yourself with Record payment on the invoice, with the bank's date and a note for the reference. ERPFlow also doesn't produce the month-end proof above, so that lives in your spreadsheet.
What it gives you to work from:
- The Invoices list filters by Overdue, Partially paid and Overpaid, and by period, so you can see what was issued in a month.
- The dashboard shows Outstanding and Overdue in your base currency. Those figures exclude VAT, with the VAT beneath, so add the two together before you compare them with the list of balances above. Part-paid invoices count only for what's left.
- Attachments on an invoice can hold a remittance or payment confirmation. They stay internal and never go to the customer.
- Mark as void and Record refund handle the corrections, if you need them.
For the second check, a quote lists the invoices made from it under Linked documents, so you can see what's been billed against it. A project can link to its customer, quotes, orders and invoices too.