An API integration is a bridge between two systems that do not communicate natively - a webshop pushing orders into accounting, or a CRM syncing with email marketing. Typical costs: €800-€3,000 for simple Zapier/Make flows, €3,000-€15,000 for custom mid-complexity work, and €15,000-€50,000+ for ERP-grade integrations.
What an API integration actually is
An API is a standardised protocol for two applications to exchange data. Instead of manual retyping, systems talk directly. This is the bedrock of effective process automation.
A typical flow: a customer buys in the webshop, the shop fires a “new order” API call to accounting, accounting issues the invoice, updates stock, and notifies the warehouse - in seconds, with no human in the loop.
Common integrations and indicative costs
| Integration | Cost (€) | Timeline |
|---|---|---|
| Webshop → Accounting (Pantheon, Minimax) | 1,500 - 5,000 | 1-3 weeks |
| CRM → Email marketing | 800 - 3,000 | 1-2 weeks |
| Payments (Stripe, Corvus, Wspay) | 2,000 - 6,000 | 2-3 weeks |
| Shipping (GLS, DPD, Post) | 1,500 - 5,000 per carrier | 1-2 weeks |
| ERP (SAP, Pantheon, Dynamics) | 8,000 - 30,000+ | 4-12 weeks |
| AI/LLM integration | 3,000 - 20,000 | 2-8 weeks |
Zapier/Make vs custom
Zapier and Make are no-code platforms with monthly fees of €20-€500. They fit when volume is under ~1,000 events per month, the workflow is a simple one-trigger-one-action mapping, and native connectors exist.
They fall short on scale (10,000+ events get expensive), complex logic, latency (1-15 minute delays), and granular error handling.
Custom integrations cost more upfront but win long-term. A €3,000 custom build for a 2,000-orders-a-month shop typically pays back within a year versus SaaS fees.
Why integrations fail
- No error handling. If the target is down, does it retry or silently lose data? Professional builds always retry.
- No monitoring. Integrations are invisible until they break. Automated alerting is mandatory.
- Scale mismatch. A pipe sized for 100 orders collapses at 10,000. Volume belongs in Discovery.
- API deprecation and skipped maintenance. Providers like Stripe and Meta change APIs constantly. A reliable partner tracks changes and patches the integration - budget 10-20 % of build cost annually for this work.
Frequently Asked Questions
Is Zapier suitable for enterprise use? Technically yes, but at scale it becomes an expensive black box that is hard to debug. Custom code is more rational once volume or logic grows.
Who maintains the integration? Under a maintenance contract, your development partner tracks API changes and applies updates. Without one, the client carries that risk alone.
Can we get a custom integration for €500? No. Architecture, security, and testing have a floor. Quotes that low usually skip the parts that make data transfer stable.
Related Articles
- ERP integrations: SAP, Dynamics & Pantheon
- Process automation: signs your business needs it
- CRM/ERP implementation cost
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