The verdict in three sentences
A DSO of 68 days means the company is financing its customers for over two months, while EU Late Payment Directive rules and French law generally cap B2B terms at 60 days. Automating dunning with an accounting integration (Pennylane, Sage, Cegid, Xero) costs between 3,000 and 12,000 EUR excl. VAT as a custom build or 100 to 400 EUR per month as SaaS, with setup in 4 to 6 weeks. Cutting DSO by 12 days releases about 150,000 EUR of cash for an SMB invoicing 4.5 million EUR a year.
Why manual dunning does not hold up
In a 60-employee SMB, collections often rely on a single accountant who checks the aged balance once a week, when time allows. As a result, first reminders go out 15 days after the due date instead of on day 1, and large accounts are never called at the right moment.
| Dunning step | Common manual practice | Recommended automated scenario |
|---|---|---|
| Pre-due reminder | None | Polite email 5 days before with the invoice attached |
| First reminder | Day +15 to +20 | Email on day +1 with a payment link |
| Second reminder | Day +30, if someone remembers | Email + SMS on day +8 |
| Phone follow-up | Rare, random | Task assigned to the account manager on day +15 |
| Formal notice | Day +60 or never | Letter generated on day +30 with the 40 EUR fixed recovery fee |
| Tracking payment promises | Sticky notes | Date logged, automatic reminder if missed |
| Time spent per month | 25 to 35 h | 6 to 8 h |
Custom build or SaaS: 2026 costs
| Option | Initial cost | Recurring cost | Best for |
|---|---|---|---|
| Native feature of the accounting tool (Pennylane, Sage, Xero) | 0 to 1,500 EUR of setup | Included or 30 to 80 EUR/month | Under 150 invoices a month, simple scenario |
| Specialized SaaS (e.g. Upflow, Chaser, Agicap) | 1,000 to 3,000 EUR setup | 100 to 400 EUR/month | 150 to 1,500 invoices a month |
| Custom automation (n8n, Make or code) | 3,000 to 12,000 EUR excl. VAT | 30 to 150 EUR/month hosting | Specific processes, multiple entities, in-house ERP |
| Pennylane API connector | Included in the custom build | 0 EUR | Daily sync of invoices and payments |
| Sage 100 or Cegid connector | 1,500 to 4,000 EUR extra depending on version | Maintenance 10 to 15%/year | On-premise or hosted software |
| SMS sending | 0 | 0.05 to 0.08 EUR per SMS | Micro-business and trade customers |
A custom build makes sense when rules depend on the customer (large accounts with supplier portals such as Coupa, deposits, disputes), or when several group companies share the same customer base.
What automation delivers
| Indicator | Before | After 6 months (estimate) |
|---|---|---|
| DSO | 68 days | 48 to 58 days |
| Invoices paid on time | 40% | 60 to 70% |
| Receivables over 90 days | 9% of outstanding | 3 to 4% |
| Monthly dunning time | 30 h | 7 h |
| Cash released (4.5M EUR revenue) | 0 | 125,000 to 250,000 EUR |
| Financing cost avoided (5% rate) | 0 | 6,000 to 12,000 EUR a year |
The maths is simple: annual revenue / 365 x DSO days saved. For 4.5 million EUR of revenue, each DSO day is worth about 12,300 EUR.
Mini case study
Claire, CFO of a 60-employee manufacturing SMB near Lyon, faces a DSO of 68 days on revenue of 4.5 million EUR, i.e. about 840,000 EUR of receivables. Accounting runs on Pennylane, but three key accounts require invoices to be uploaded to their supplier portal.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
She chooses a custom automation at 8,500 EUR excl. VAT, with scenarios per customer segment, SMS for trade customers and phone follow-up tasks for sales staff. After 6 months, DSO falls to 56 days: 12 days x 12,300 EUR = 147,600 EUR of cash released. She repays a credit line at 5%, saving about 7,400 EUR of interest a year, and recovers 23 hours of accounting work per month. The project pays for itself in year one.
FAQ
How much does invoice dunning automation cost in 2026?
From 3,000 to 12,000 EUR excl. VAT for a custom solution connected to your accounting system, or 100 to 400 EUR per month for a specialized SaaS tool. The native feature of Pennylane, Sage or Xero is often enough below 150 invoices a month.
How long does setup take?
Allow 4 to 6 weeks: one week to design the scenarios, 2 to 3 weeks to build the connector and templates, then 1 to 2 weeks of testing on a sample of 50 customers.
Do automated reminders damage customer relationships?
Not if the tone escalates gradually and strategic accounts are handled by a person. In practice, 60 to 70% of late payments are simple oversights, and a reminder 5 days before the due date resolves them.
Should we charge the 40 EUR fixed recovery fee?
Under the EU Late Payment Directive, a minimum 40 EUR compensation is due for each late B2B invoice, on top of late interest. The tool can mention it automatically in the formal notice, while the decision to claim it stays with the CFO.
How does automation prepare for e-invoicing?
The connector retrieves invoice statuses from the certified e-invoicing platform as mandates come into force (France: September 2026 to September 2027 depending on company size). Statuses such as rejected or disputed then pause reminders, avoiding sending them by mistake.
Let's scope your project. We review your aged balance, define dunning scenarios and price a connector to your accounting software, with an indicative budget of 3,000 to 12,000 EUR excl. VAT and go-live in 4 to 6 weeks. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
