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ERP/CRM API integration cost for a custom app in Amsterdam (2026)

Mohamed Bah·Fondateur, Kolonell
September 5, 2026
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ERP/CRM API integration cost for a custom app in Amsterdam (2026)

ERP/CRM API integration cost for a custom app in Amsterdam (2026)

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The verdict in three sentences

An API integration between your web app and an existing ERP/CRM (Sage, SAP, Salesforce, HubSpot) costs between EUR 8,000 and EUR 30,000 excl. VAT per connector in 2026, with price driven by data mapping and error-handling robustness, not the number of fields. For a simple, low-volume need, an iPaaS (Make, n8n, Zapier) at EUR 20-500/month is often enough. The real ROI is measured in eliminated double data entry: past 10 hours/week, a custom connector pays for itself within a year.

What drives a connector's price

A connector is not a simple pipe: it translates, validates, replays and logs. The budget concentrates on mapping (matching your fields to the ERP's), error handling (what happens if Sage is down?) and real-time synchronization webhooks.

ItemLow complexityMedium complexityHigh complexity
Scoping & field mappingEUR 1,500EUR 3,500EUR 6,000
Connector developmentEUR 4,000EUR 9,000EUR 15,000
Error handling & replayEUR 1,000EUR 2,500EUR 5,000
Real-time webhooksEUR 800EUR 2,000EUR 4,000
Testing & acceptanceEUR 1,200EUR 2,500EUR 4,500
Total excl. VAT (2026)EUR 8,500EUR 19,500EUR 34,500

High complexity typically means SAP with deep business rules; Salesforce and HubSpot, with modern well-documented APIs, usually land in the low-to-medium range.

One-off custom integration vs iPaaS

Many SMEs confuse the two. iPaaS excels at standard, low-volume flows; custom becomes worthwhile as soon as business logic or volume climbs.

CriterioniPaaS (Make/n8n/Zapier)Custom connector
Upfront costEUR 0-1,500 (setup)EUR 8,000-30,000 excl. VAT
Recurring costEUR 20-500/monthEUR 80-300/month (maintenance)
Suitable volume< 10,000 ops/monthUnlimited
Complex business logicLimitedFull
Time to deploy1-3 weeks4-10 weeks
Vendor lock-inHighNone (you own the code)

n8n, self-hostable, is a good compromise: controlled cost and no per-operation billing. Zapier is the fastest to start but gets expensive at volume.

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Mini case study

Claire, CFO of a 45-person industrial SME in Amsterdam, enters every order twice: once in the sales app, once in Sage. Her teams spend 15 hours a week on this, at a loaded cost of EUR 35/h, i.e. EUR 525/week or about EUR 27,300/year. A bidirectional Sage connector at EUR 18,000 excl. VAT plus EUR 150/month maintenance comes to EUR 19,800 in year one. From year one, net savings exceed EUR 7,500, and year two frees up over EUR 25,000 in savings, not counting fewer entry errors.

FAQ

How much does a simple Salesforce integration cost? To sync contacts and opportunities one-way, expect EUR 8,000 to 12,000 excl. VAT in 2026. A bidirectional sync with deduplication rules rises to EUR 15,000-20,000.

Is an iPaaS enough to connect my ERP? Yes if your volumes stay under ~10,000 ops/month and logic is standard. Beyond that, Zapier's monthly cost quickly exceeds the maintenance cost of an owned connector.

What happens if the ERP is down? A good connector queues operations and replays them automatically. Budget EUR 1,000 to 5,000 for this resilience: it separates a pro connector from a fragile script.

Must the connector be maintained over time? Yes: APIs evolve (Salesforce ships 3 versions/year). Budget EUR 80 to 300/month of maintenance to absorb version changes and monitoring.

How long does delivery take? From 4 weeks for a simple flow to 10 weeks for a bidirectional SAP integration with full acceptance testing.

Let's scope your project. Tell us which ERP/CRM to connect, the flow direction and monthly volume: we'll tell you whether a EUR 300/month iPaaS is enough or you need a custom connector. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.

Tags:#API integration#ERP CRM#iPaaS#middleware#Amsterdam#connector
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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.