The verdict in three sentences
A custom supplier portal for an Amsterdam manufacturer with 300 active suppliers costs between EUR 35,000 and 70,000 excluding VAT in 2026, for about 4 months of development. It centralises tenders, certificates and invoices, connects to SAP and saves on average 12 hours per week per buyer. Against a suite like Coupa billed at EUR 40 to 80 per user per month, custom development pays off as soon as you open access to suppliers and several internal departments.
What the portal actually does
Today, your procurement team juggles emails, tracking spreadsheets and SAP. ISO certificates, Chamber of Commerce (KvK) extracts and insurance documents expire without warning, tenders go out as attachments and invoices arrive through three different channels. The portal brings everything into one space: each supplier has an account, uploads documents, answers tenders and tracks payments.
| Module | Function | Indicative 2026 budget (EUR) |
|---|---|---|
| Supplier onboarding | Profile, legal documents, ESG questionnaire, approval | 6,000 to 11,000 |
| Certificate management | Upload, expiry dates, automatic reminders 30 days ahead | 4,000 to 7,000 |
| Tenders | Specifications, Q&A, scoring grid | 8,000 to 16,000 |
| Invoice upload and tracking | PDF or UBL e-invoice upload, status, PO matching | 6,000 to 12,000 |
| SAP connector | Suppliers, purchase orders, payment status (API or IDoc) | 7,000 to 15,000 |
| Procurement dashboard | Lead times, compliance rate, spend by category | 3,000 to 6,000 |
| Security and rights | Internal SSO, roles, audit log, GDPR | 1,000 to 3,000 |
The core with onboarding, certificates and invoices sits around EUR 35,000. Adding full tenders and a two-way SAP connector pushes it toward EUR 70,000.
Custom build or Coupa: the 5-year comparison
| Criterion | Custom portal | Coupa or equivalent suite |
|---|---|---|
| Initial cost | EUR 35,000 to 70,000 | EUR 15,000 to 40,000 deployment |
| Recurring cost | EUR 600 to 1,200/month (hosting and maintenance) | EUR 40 to 80 per user per month |
| 5-year cost, 25 internal users | EUR 71,000 to 142,000 | EUR 75,000 to 160,000 |
| Supplier access | Unlimited, no extra cost | Often included, paid modules |
| Fit with your processes | Full | Configuration within vendor limits |
| Code ownership | Yes | No |
| Time to go-live | 4 months | 3 to 9 months depending on integrator |
These are 2026 orders of magnitude. Coupa remains relevant for a multi-country group with more than 200 buyers. For a manufacturer with 10 to 30 internal users and specific processes, custom is usually cheaper from year three.
The 4-month plan
| Month | Steps |
|---|---|
| 1 | Scoping with buyers, SAP mapping, mock-ups |
| 2 | Onboarding, certificates, supplier space |
| 3 | Tenders, invoices, SAP connector |
| 4 | Acceptance, pilot with 30 suppliers, rollout to 300 |
Mini case study
Pieter, procurement director of an engineering manufacturer in Amsterdam, manages 6 buyers and 300 active suppliers. He chooses a portal at EUR 52,000 with EUR 900 a month of maintenance. Each buyer saves 12 hours a week, 72 hours for the team. Over 45 working weeks at a loaded cost of EUR 45 an hour, that is EUR 145,800 a year of freed time. Even valuing only a third of it, EUR 48,600, the portal pays back in about 16 to 17 months, maintenance included, not counting penalties avoided on expired certificates.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
FAQ
What does a custom supplier portal cost in Amsterdam in 2026?
Between EUR 35,000 and 70,000 depending on modules and the depth of the SAP integration. A core with onboarding, certificates and invoices starts around EUR 35,000.
Is the SAP connection risky?
Not if it is scoped in month one with your SAP team. It represents EUR 7,000 to 15,000 and runs through API or IDoc depending on your version (ECC or S/4HANA).
Does the portal handle e-invoicing?
Yes, it accepts UBL and Peppol-ready formats and can forward invoices to your access point. Peppol e-invoicing is already standard for Dutch public procurement and spreading fast in B2B.
How long to onboard 300 suppliers?
Allow 4 to 6 weeks after the pilot, with an invitation email and a 2-page guide. Typically 70% of suppliers are active in the first month.
What does maintenance cost?
Between EUR 600 and 1,200 a month, EU hosting, backups and fixes included. Enhancements are quoted separately at a fixed price.
Let's scope your project. Tell us your supplier volumes, SAP version and priorities: we will price a portal between EUR 35,000 and 70,000 with a 4-month plan. 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.
