Every e-invoicing project eventually needs a business case. Someone has to sign off the budget, approve the IT resource, and agree to the operational change — and that person will ask what the return looks like. Vague answers about "efficiency gains" and "going digital" do not get projects approved.
This post gives you a practical framework for building that business case, with a worked example for a mid-sized Swiss company. The numbers are illustrative rather than universal, but the structure is directly usable.
The cost components to measure
A credible ROI calculation needs to start from your current costs, not from generic industry benchmarks. The benchmarks are a useful sense check, but your CFO will ask for your numbers. There are four cost areas to measure on the outbound side (accounts receivable) and four on the inbound side (accounts payable).
Accounts receivable costs
Invoice production cost. How long does it take to produce and send an invoice today? Include the time to create the document, any internal approval step, printing or exporting to PDF, and sending — whether that is printing and posting, emailing, or uploading to a customer portal. Multiply by your average fully loaded staff cost per hour.
Chasing and dispute resolution. What percentage of your invoices generate a query or dispute, and how long does resolving one take? This tends to be significantly underestimated because it is distributed across multiple people and not tracked systematically. A realistic figure for a company processing invoices manually is 5–15% dispute rate, with 30–90 minutes per dispute.
Late payment and financing cost. What is your average days sales outstanding (DSO)? What would a 5-day reduction in DSO be worth in reduced financing cost or freed working capital? For a company with CHF 10 million in annual revenue and a cost of capital of 5%, each day of DSO improvement is worth roughly CHF 1,400 per year.
Archiving and audit support. How much staff time goes into finding specific invoices during audits, year-end close, or customer queries? And what are your physical storage costs if you are still archiving paper?
Accounts payable costs
Invoice processing cost per invoice. This is the total cost — staff time plus system costs — to take an invoice from receipt through to payment approval. Break it down between invoices that flow straight through and those that require manual intervention. Industry benchmarks for manual processing range from CHF 12 to CHF 30 per invoice; straight-through processing with structured data typically comes in at CHF 1–4.
Exception handling. What is your current exception rate — the percentage of invoices that require a human to intervene before they can be approved? Track this for a month if you do not already know it. Exceptions are where most of the cost in a manual AP process sits.
Duplicate payment and error rate. What has your company paid incorrectly in the past year — duplicates, wrong amounts, payments to wrong accounts — and what did it cost to recover? This number tends to be uncomfortable to calculate accurately but is a legitimate cost of the current process.
Supplier query handling. How much time does your AP team spend answering supplier calls and emails asking about invoice status? This is real cost that disappears almost entirely when suppliers can check status themselves through a structured channel.
A worked example
Take a Swiss manufacturing company processing 600 outbound and 800 inbound invoices per month. The current process is largely manual — PDFs sent by email on the outbound side, PDFs received and keyed into the ERP on the inbound side.
Current state costs (annual):
| Cost area | Assumption | Annual cost |
|---|---|---|
| AP: manual processing at CHF 18/invoice | 800 × 12 × CHF 18 | CHF 172,800 |
| AP: exception handling (20% rate, 45 min each) | 1,920 exceptions × 0.75h × CHF 80/h | CHF 115,200 |
| AR: invoice production (8 min per invoice) | 7,200 × 0.13h × CHF 80/h | CHF 74,880 |
| AR: dispute handling (8% rate, 60 min each) | 576 disputes × 1h × CHF 80/h | CHF 46,080 |
| AR: DSO financing cost (38-day DSO) | Conservative estimate | CHF 28,000 |
| Archiving and audit support | Estimate | CHF 15,000 |
| Total current cost | CHF 451,960 |
Future state with structured e-invoicing (annual):
| Cost area | Assumption | Annual cost |
|---|---|---|
| AP: STP processing at CHF 3/invoice (70% STP rate) | 6,720 × CHF 3 | CHF 20,160 |
| AP: remaining manual processing at CHF 18 | 2,880 × CHF 18 | CHF 51,840 |
| AP: reduced exception handling (6% rate) | 576 exceptions × 0.75h × CHF 80/h | CHF 34,560 |
| AR: invoice production (automated, 2 min per) | 7,200 × 0.033h × CHF 80/h | CHF 19,008 |
| AR: dispute handling reduced to 2% | 144 disputes × 1h × CHF 80/h | CHF 11,520 |
| AR: DSO improvement (5-day reduction to 33 days) | CHF 14,000 | |
| Archiving (digital, PDF/A-3 archive) | CHF 5,000 | |
| Total future cost | CHF 156,088 |
Annual saving: CHF 295,872
Implementation costs for a company of this size typically run CHF 40,000–80,000 for a well-scoped project (ERP configuration, service provider setup, testing, and supplier onboarding). That gives a payback period of under four months.
What the model often misses
The calculation above covers direct operational costs. A complete business case should also consider:
Compliance cost avoidance. If your company invoices Swiss federal bodies, non-compliance with the 2026 mandate creates real risk — invoices rejected, payments delayed, relationship strain. Quantifying this as avoided cost reinforces the case.
Early payment discount capture. As covered in the dynamic discounting post, a faster AP approval cycle opens the window for suppliers to offer early payment discounts. Even capturing a 1% discount on 20% of your payables can add meaningful value — for CHF 5 million in annual payables that would be CHF 10,000 per year on the portion where discounts are available.
Supplier financing cost. If your suppliers are currently borrowing to bridge payment gaps because your AP cycle is slow, some of that cost is ultimately embedded in the prices they charge you. Faster, more predictable payment sometimes creates room for price negotiation — harder to quantify but real.
Staff redeployment value. The hours freed from manual invoice processing can go to higher-value work. This is not a cash saving unless you reduce headcount, but it is a capacity gain. In a finance team already stretched, this often matters more than the CHF number.
How to present it
When presenting the business case to a CFO or finance committee, structure it in three sections:
Current state cost — what you are spending now. Use your own data, not benchmarks. If you need to estimate hours spent on invoice handling, run a two-week time-tracking exercise before building the case. The precision signals that the numbers are real.
Future state cost — what you expect to spend after implementation. Be conservative on the efficiency gains. A 70% straight-through processing rate is achievable, but do not promise 90% in year one. Under-promise and over-deliver on operational savings.
Implementation investment and payback — total project cost, expected annual savings, and the resulting payback period. Most Swiss companies achieve payback within 6–18 months. If your numbers show longer, revisit your implementation cost estimate — projects that drag in that direction are usually over-scoped for the volume they handle.
The KPIs to track after go-live are useful to include in the business case as the metrics you will use to report actual performance against the projected savings. Committing to measurement upfront signals confidence in the numbers and makes the post-implementation review far easier.