The verdict in three sentences
A web app that does not talk to your ERP creates double entry, errors and inconsistent data. In 2026, an API integration is priced between 8,000 and 25,000 EUR depending on the number of flows, ships in 4 to 10 weeks and removes up to 80% of manual data entry. The key trade-off: real-time API for critical flows, batch synchronisation for the rest, with a middleware layer if you must orchestrate several systems.
Real-time API, flat files or iPaaS?
Three architectures dominate. A real-time REST API offers fresh data but requires the ERP to expose reliable endpoints. Flat files (CSV/EDI) are simple and robust but introduce latency. An iPaaS (middleware such as Make, n8n, Mulesoft) orchestrates several systems with queues and replay, at the cost of a monthly subscription.
| Criterion | Real-time REST API | Flat files (batch) | iPaaS / middleware |
|---|---|---|---|
| 2026 integration cost | 12,000-25,000 EUR | 8,000-15,000 EUR | 10,000-20,000 EUR |
| Recurring cost | hosting only | near zero | 200-800 EUR/month |
| Data freshness | < 5 min | 1-24 h | < 5 min |
| Fault tolerance | to be built | high | native (replay, queues) |
| Multi-system complexity | high | low | controlled |
| Implementation timeline | 6-10 weeks | 4-6 weeks | 5-8 weeks |
The right choice depends on criticality: an order flow demands real time, a monthly accounting export is fine with a nightly batch.
The pitfalls that blow the budget
Most overruns come from underestimating edge cases: inconsistent data formats, an ERP with no documented API, error and duplicate handling.
| Pitfall | Impact | Countermeasure |
|---|---|---|
| ERP with no standard API | +30-50% cost | middleware or dedicated connector |
| No webhook handling | data loss | queues + replay |
| No reconciliation | duplicates, gaps | idempotency + logs |
| Too-frequent sync | ERP overload | batch for non-critical flows |
| Undefined sync SLA | internal disputes | contracted target < 5 min |
| No degraded mode | total blockage | local queue + auto-recovery |
Serious scoping defines each flow, its direction, frequency and recovery mode before the first line of code.
Mini case study
Julien, CIO of a mid-sized distributor in Berlin, wants to connect a field order-taking app to his Sage ERP. His reps re-key 100% of orders in the evening, 3 h/day for 6 reps, around 90 h/week of entry. He invests 18,000 EUR in a REST API integration plus an iPaaS at 350 EUR/month to handle queues and replay. By removing 80% of entry, he recovers the equivalent of 72 h/week, over 110,000 EUR a year of sales time returned to selling. Payback in about 2 months.
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FAQ
How much does an ERP integration cost in 2026?
The ballpark is 8,000 to 25,000 EUR depending on the number of flows, the ERP's API availability and the need for real time. An iPaaS adds 200 to 800 EUR/month of recurring cost.
Real time or batch?
Real time (SLA < 5 min) is required for orders and stock. For accounting exports or stable reference data, a nightly batch cuts cost without hurting the business.
My ERP has no modern API, is it still possible?
Yes, via a middleware or dedicated connector that reads the database or consumes exports. Budget 30 to 50% extra cost compared with an ERP that has a documented REST API.
How do I avoid data loss?
By handling webhooks with queues and replay, making operations idempotent and logging every exchange. A degraded mode with a local queue prevents any blockage during an ERP outage.
What concrete gain should I expect?
Removing double entry typically reaches 80%, cutting errors, making stock reliable and freeing hours for operational teams.
Let's scope your project. List your flows, your ERP and your freshness needs: we will frame an integration between 8,000 and 25,000 EUR deliverable in 4 to 10 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.
