The verdict in three sentences
A custom subscription billing system for a company in Amsterdam costs, in 2026, between 70,000 and 130,000 EUR, over a 3 to 5 month project. It replaces manual monthly invoicing with plans, proration and automated dunning, compliant e-invoicing (Peppol, UBL) and a direct link to the accounting software. Against Chargebee or Stripe Billing (0.5 to 0.8% of billed revenue), custom becomes cost-effective above roughly 15 to 20 million EUR billed a year, or when complex contract logic does not fit the platforms.
The building blocks of a subscription system
Invoicing 2,200 contracts by hand means recalculating every month the amendments, mid-period plan changes and negotiated discounts. Errors cost you credit notes, disputes and late payments.
| Component | Role | 2026 cost (EUR) |
|---|---|---|
| Plan and add-on catalog | Plans, tiers, commitments, discounts | 8,000 - 14,000 |
| Proration and amendment engine | Mid-month upgrades and downgrades | 11,000 - 19,000 |
| Invoice generation | Monthly, quarterly, annual runs | 7,000 - 13,000 |
| Compliant e-invoicing | Peppol UBL format, EU VAT rules | 9,000 - 17,000 |
| Automated dunning | Email, SMS, escalation, service suspension | 6,000 - 11,000 |
| Payment collection | SEPA direct debit, iDEAL, card, reconciliation | 8,000 - 16,000 |
| Accounting connection | Journal entries, matching, export to Exact or Twinfield | 7,000 - 14,000 |
| Customer portal | Invoices, payment methods, plan changes | 7,000 - 14,000 |
The proration engine concentrates the complexity. A customer adding 15 seats on the 12th of the month, on an annual commitment with a 10% discount, must get an exact invoice without human intervention.
Custom build or Chargebee and Stripe Billing
International platforms are mature and quick to deploy, and they handle SEPA and iDEAL well in the Netherlands. Their limits show up with unusual contract rules and as billed revenue grows.
| Criterion | Chargebee / Stripe Billing | Custom build |
|---|---|---|
| Upfront cost | 6,000 - 18,000 EUR (integration) | 70,000 - 130,000 EUR |
| Recurring cost | 0.5 to 0.8% of billed revenue | 12,000 - 21,000 EUR / yr |
| On 18,000,000 EUR billed per year | 90,000 - 144,000 EUR / yr | 12,000 - 21,000 EUR / yr |
| Peppol e-invoicing | Add-on or partner | Native |
| Complex contract rules | Workarounds needed | Built to fit |
| Time to go live | 4 to 8 weeks | 3 to 5 months |
| Vendor lock-in | High | Code owned by the company |
Mini case study
Sanne, CFO of an IT services company in Amsterdam, invoices 2,200 maintenance contracts every month, for 18,000,000 EUR a year. Two accountants spend 9 days a month on it, about 70,000 EUR a year in loaded time, and 3% of invoices lead to a credit note. The custom system, quoted at 100,000 EUR plus 17,000 EUR a year of maintenance, cuts the cycle to 1 day and brings average payment time from 52 to 38 days, freeing about 690,000 EUR of cash. With Stripe Billing at 0.6%, the recurring cost would be 108,000 EUR a year. Compared with that option, the project pays back in about 14 months.
FAQ
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Does the system handle Dutch and EU e-invoicing?
Yes, the compliance component (9,000 to 17,000 EUR) produces Peppol UBL invoices and applies EU VAT rules, including reverse charge for B2B customers in other member states.
Can we migrate the 2,200 existing contracts?
Yes. Migrating contracts, renewal dates and discounts costs 5,000 to 11,000 EUR depending on how clean the current spreadsheets are, with a parallel control run for one month.
Won't automated dunning annoy customers?
The sequence is configurable: reminder at D-3, follow-up at D+7, call at D+15, suspension at D+30 only after approval. In practice, 60 to 70% of late payments are settled after the first reminder.
Which accounting integrations are possible?
Journal export to Exact Online, Twinfield or AFAS, with automatic payment matching. Budget 7,000 to 14,000 EUR.
When is Stripe Billing the better choice?
If you bill under 5,000,000 EUR a year with standard plans: the 0.5 to 0.8% fee then stays below the cost of a custom project.
Let's scope your project. Tell us your number of contracts, plans and accounting software, and we will cost the system with a 3-year comparison against market platforms. 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.
