The verdict in three sentences
A Berlin purchasing group that onboards 1,200 suppliers for 300 member stores by email and spreadsheet loses control of compliance files and payment questions. A custom supplier portal that centralises the supplier file (trade register extract, tax and social insurance certificates, ESG questionnaire), online tenders and invoice status can free 2 FTE of admin work in a 5 month project. In the German market, budgets run from 70,000 to 130,000 EUR (2026 order of magnitude), to compare with SaaS licences at 25 to 60 EUR per supplier per year.
What onboarding by email and Excel really costs
The head of procurement sees three problems recur. Tax clearance certificates (Bescheinigung in Steuersachen) and social insurance clearances expire without anyone chasing them. Tenders go out as attachments to 40 suppliers and come back in a dozen formats. Suppliers phone accounts payable to ask about their invoices.
| Task | Estimated annual volume | Manual time | With portal | Time saved |
|---|---|---|---|---|
| Collecting and chasing tax and social insurance certificates | 2,400 documents | 0.25 h each | Upload and automatic alerts | 480 h |
| Updating trade register extracts | 1,200 documents | 0.15 h each | Online upload with date check | 140 h |
| Annual ESG questionnaire | 1,200 responses | 0.5 h each | Online form and scoring | 480 h |
| Tenders and RFQs | 60 tenders | 12 h each | Standard response grid | 480 h |
| Invoice status questions | 6,000 requests | 0.15 h each | Status visible to supplier | 720 h |
| New supplier records | 150 new records | 2 h each | Validated self-registration | 200 h |
The total passes 2,500 hours a year, more than 1.5 FTE at 1,600 hours. As the supplier base grows, freeing 2 FTE for analysis work is a realistic goal. Groups subject to the Supply Chain Due Diligence Act (LkSG) also gain an auditable risk record per supplier.
Custom build or SaaS licence: 5 year comparison
Supplier management suites usually bill per supplier or per user. A custom portal costs more upfront but fits purchasing group rules: members, framework agreements, year-end rebates.
| Criterion | SaaS licence | Custom portal |
|---|---|---|
| Upfront cost | 15,000 to 35,000 EUR configuration | 70,000 to 130,000 EUR |
| Annual cost | 30,000 to 72,000 EUR (25 to 60 EUR x 1,200 suppliers) | 9,000 to 16,000 EUR maintenance and hosting |
| 5 year cumulative cost | 165,000 to 395,000 EUR | 115,000 to 210,000 EUR |
| Member-specific rules | Limited to configuration | Built around your agreements |
| Data and code ownership | Vendor | Purchasing group |
| Time to go live | 2 to 3 months | 5 months |
At Kolonell, this kind of portal falls into our complex application category: 7,000,000 to 15,000,000+ FCFA, that is 10,670 to 22,870+ EUR, with the exact amount set in the quote after a scoping workshop. EU hosting and maintenance (53 to 183 EUR per month depending on level) are scoped in the same quote.
Modules and the 5 month timeline
Month 1 maps the onboarding process and approval rules. Month 2 delivers the supplier area: registration, document upload, expiry alerts 30 days ahead. Month 3 adds tenders: specifications, price grid, automatic bid comparison. Month 4 connects the portal to the ERP to show invoice status (received, approved, cleared for payment, paid). Month 5 covers testing with 50 pilot suppliers and phased rollout.
E-invoicing makes the project timelier: since 1 January 2025 every German business must be able to receive structured e-invoices (XRechnung or ZUGFeRD), with issuing obligations phasing in from 2027. The portal does not replace that channel, it shows suppliers the resulting status, which removes most of the calls.
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Katrin, head of procurement at the group, puts current workload at 2,500 hours a year at 48 EUR per loaded hour, 120,000 EUR. The portal costs 100,000 EUR plus 12,000 EUR a year. If 80 % of the hours are saved, the annual gain is 96,000 EUR, minus 12,000 EUR running costs, 84,000 EUR net. Payback comes in about 14 months. Against a licence at 45 EUR per supplier, 54,000 EUR a year, the 5 year gap still favours the custom portal by more than 100,000 EUR.
FAQ
Will suppliers actually use the portal?
Yes, if uploading documents is a condition for listing and payment. Groups that enforce it usually reach 85 to 95 % adoption within 6 months.
Can certificate validity be checked automatically?
The portal checks dates and document type on upload, and sends an alert 30 days before expiry. Manual review remains for the first upload only.
How should the ESG questionnaire work?
Structure it in 20 to 40 scored questions, so suppliers can be ranked and their progress tracked year on year, which also feeds LkSG risk analysis.
Does the portal need an ERP connection?
For invoice status, yes. A daily sync is enough in most cases and accounts for 15 to 20 % of the budget.
What if we change ERP later?
The connector is isolated from the rest of the portal: only that module needs rework, a few weeks of effort.
Let's scope your project. Tell us about your onboarding process, volumes and ERP, and we will scope the priority modules and a 5 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.
