By Diogo Cavazzini, Product & Marketing Director, PaperLess Europe
1000+ Sage Implementations | Expert in AP Automation, OCR and PEPPOL Compliance
Ask most Finance Directors what it costs to process an invoice and you will get a rough figure based on postage, printing and maybe a share of someone’s salary. Ask what it actually costs, including the minutes spent keying data, the time chasing approvals, the rework on errors and the hours lost filing and retrieving documents, and the honest answer is usually that nobody has worked it out.
That gap matters, because you cannot build a credible business case for automation, or for anything else, without knowing what the current process costs. This article sets out the calculation properly, the same one we use with prospects before any conversation about software, so you can run it against your own numbers before you read another vendor claim.
Why the obvious cost is not the real cost
The instinct is to think about invoice processing cost in terms of the accounts team’s salaries, divided by however many invoices they handle. That number is real, but it hides more than it reveals. It does not separate the minutes spent on invoices that sail through from the hours lost on the ones that do not. It says nothing about rework, about invoices posted with the wrong nominal code or duplicated and later spotted, corrected and re-entered. And it almost never includes the time spent filing invoices in the first place, or digging them out again three months later when a supplier queries a payment or an auditor asks for evidence.
A proper cost calculation separates these components, because each one responds differently to automation, and because knowing which one is largest tells you where the real opportunity sits in your business.
The five components of true invoice processing cost
1. Processing time per invoice
From the moment an invoice is received to the moment it is posted, including data entry, coding and any matching against a purchase order. For a manual process this typically runs from five to fifteen minutes per invoice depending on complexity and how much of it involves re-keying from a PDF or paper document.
2. Fully loaded staff cost
Salary plus employer costs, National Insurance, pension contributions and the rest, for the people who touch invoices. Finance administration roles typically sit between 18 and 28 pounds an hour fully loaded in most UK markets, though this varies by region and seniority.
3. Rework and error correction
Every business has an error rate on manual data entry, whether that is a mistyped amount, a wrong nominal code, a missed approval step or a duplicate payment. Industry studies consistently place manual AP error rates between 1% and 4% of invoices processed, and each error costs considerably more to fix than the original entry cost to make.
4. Filing and retrieval time
Archiving invoices takes time even when it is just saving a PDF into a folder with a sensible name. Retrieving them again, for a supplier query, an internal approval, a VAT inspection or a year-end audit, takes longer still, especially once volumes are measured in years rather than months. Most finance teams underestimate this figure until they are asked to total it up.
5. The cost of delay itself
Harder to quantify but real: late payments that damage supplier relationships or forfeit early payment discounts, management accounts delayed because invoices are still working through the approval chain, and the opportunity cost of an experienced finance professional spending their week on data entry instead of analysis.
Putting the numbers together
Once you have those five components, the calculation itself is simple multiplication: invoices per month, multiplied by minutes per invoice, converted to hours, multiplied by the fully loaded hourly cost, plus the additional cost of rework and of filing and retrieval time. For a business processing 500 invoices a month at ten minutes each and 22 pounds an hour, the processing time alone comes to roughly 1,800 pounds a month before rework or filing costs are added. Multiply that by twelve and the number most Finance Directors have never actually calculated starts to look considerably larger than they expected.
Rather than asking you to build a spreadsheet from scratch, we turned this exact calculation into a free tool. Our AP automation savings calculator lets you enter your own invoice volume, processing time, staff cost, error rate and filing time, in whichever currency you work in, and see the current cost of your process against what it would look like automated. No email address is required to see the result.
The PaperLess AP Automation Savings Calculator
What automation actually changes in each component
This is the part worth understanding before you use the calculator, because it explains where the assumptions behind it come from. Across PaperLess Automatic Invoice Recognition implementations, processing time typically falls by around 80%, since OCR reads the invoice and the team reviews rather than types.
- Rework and errors. With data captured directly from the document rather than typed by hand, and with duplicate detection built in, error rates typically fall to well under 1% of invoices processed.
- Filing and retrieval. Every invoice is archived automatically and attached to its transaction in Sage, Xero or SAP Business One, which is why retrieval time typically drops by around 90%. A ten second lookup replaces a search through folders or filing cabinets.
- Approval delay. Invoice Approval workflows route each invoice to the right person automatically, with escalation rules for anything left sitting too long, which is what removes the walked-to-a-desk or lost-in-an-inbox delay from the process entirely.
Businesses with purchase orders in place add a further layer: Purchase Order Matching posts correctly matched invoices with no manual review at all, which is why the businesses with the highest PO coverage tend to see the largest overall savings when they run the calculator.
A worked example
Take a business processing 500 invoices a month, ten minutes each, at a fully loaded cost of 22 pounds an hour, a 4% rework rate and 10 hours a month spent filing and retrieving documents. On the assumptions above, that business would see processing time fall to roughly two minutes per invoice, rework drop toward 0.5%, and filing and retrieval time fall by 90%. Run through the full calculation, the saving typically lands in the tens of thousands of pounds a year, before any consideration of faster month end reporting or reduced audit preparation time, which do not show up in a pounds and pence figure but are real all the same.
Every business’s numbers are different, which is exactly why we built the calculator rather than publishing a single average figure that would not apply to most readers. Our customer case studies show what these savings look like in practice once a real implementation is running, across manufacturing, hospitality and services businesses of different sizes.
From the calculation to the decision
A savings figure is a starting point, not a business case on its own. If the numbers from the calculator look significant for your business, the next step is seeing the process working against your own invoices rather than reading further projections. Book a free demo and we will show you exactly how capture, approval and posting work together, so you can judge for yourself whether the numbers hold up in practice.
