What does it cost to process one invoice by hand?

Why the published benchmarks do not help

Search for this and you will find figures from about £2 to over £30 per invoice. Both extremes are real, and neither is about you.

The low figures come from large enterprises with matched purchase orders and mature automation, spreading fixed costs across hundreds of thousands of invoices. The high figures usually come from vendors selling accounts-payable software. A ten-person firm keying invoices out of an inbox sits nowhere near either.

The only figure worth acting on is the one you measure. It takes about twenty minutes.

The calculation

Cost per invoice = (minutes end to end ÷ 60) × loaded hourly cost.

End to end means from the invoice arriving to it being approved and scheduled for payment, including everything that happens in between. Loaded hourly cost is what the person costs the business, not their salary divided by hours — see the costing method for why that distinction matters more than any other input.

Multiply by monthly volume and by twelve, and you have the annual figure. 400 invoices a month at £3.30 is around £15,800 a year on one process.

The minutes people forget

Ask how long an invoice takes and you will be told how long a clean invoice takes. Clean invoices are not the problem.

• The invoice arrives with no purchase order reference, so someone works out which job it belongs to
• The line items do not match what was agreed, so someone emails the supplier and waits
• It needs approval from someone who is on site and not at a desk
• It was keyed into the wrong nominal code and gets corrected at month end
• The supplier chases for payment because nobody told them it was queried

A process quoted at four minutes routinely measures at nine or ten once those are counted. And it is precisely the queries, chasing and rekeying that automation removes most reliably, so leaving them out understates the opportunity as well as the cost.

Measure the exceptions separately

Split the invoices that go straight through from the ones that do not. Typically 10 to 20 per cent need intervention, and they can cost more than everything else combined because they interrupt someone senior.

That split changes what is worth doing. Sometimes the answer is not to automate the whole process but to automate the routing of exceptions, so the finance director stops being the queue.

What to do with the number

If it is small, leave it alone. Plenty of processes are genuinely cheap to run by hand, and the honest conclusion is to do nothing.

If it is large, you now have a defensible figure to hold any supplier to — including us. Our pricing is a proportion of exactly this number, which is why we insist on measuring it and agreeing it in writing before anything is built. The calculator does the arithmetic if you would rather not.