The verdict in three sentences
A solid ERP-CRM API integration runs between 18,000 and 45,000 EUR in Berlin in 2026, depending on the number of synced objects and the complexity of your business rules. Expect 6 to 12 weeks of build time and 350 to 800 EUR/month of maintenance to absorb API changes and error replays. The return comes from eliminating double data entry: around 20 hours/month saved and 45% fewer errors on customer and order records.
What a connector actually covers
A professional connector is not just pushing data one way. It handles field mapping, deduplication, two-way sync, a retry queue for failures, and logging for audit. Price differences come mainly from the number of objects (accounts, contacts, quotes, orders, invoices, stock) and the sync mode.
| Scope | Synced objects | Mode | 2026 price (EUR) | Timeline |
|---|---|---|---|---|
| Simple connector | Accounts + contacts | Nightly batch | 18,000 - 22,000 | 6 wks |
| Standard connector | + Quotes + orders | Near real time | 24,000 - 32,000 | 8 wks |
| Advanced connector | + Invoices + stock | Real-time two-way | 34,000 - 45,000 | 10-12 wks |
| Multi-entity | Several companies/countries | Real time + rules | 45,000 - 65,000 | 12-16 wks |
| Historical migration | Data reprise | One-shot + checks | +5,000 - 11,000 | +2 wks |
A senior integration developer's day rate in Berlin sits between 650 and 1,000 EUR in 2026. A standard connector therefore represents 30 to 45 person-days including design and testing.
Cost items not to forget
The build price is only part of the equation. Third-party APIs sometimes charge for access (Salesforce, HubSpot, SAP tiers), and evolutionary maintenance is essential whenever the vendor changes its API version.
| Item | Frequency | 2026 order of magnitude |
|---|---|---|
| Initial build | One-shot | 18,000 - 45,000 EUR |
| Maintenance | Monthly | 350 - 800 EUR/month |
| Monitoring + alerting | Monthly | 100 - 250 EUR/month |
| Third-party API licences | Monthly | 0 - 600 EUR/month |
| Major upgrade | Yearly | 4,000 - 9,000 EUR |
Mini case study
Nicolas, IT director of an industrial trading SME in Berlin (85 staff), ran an ERP and a CRM with no link. Three assistants re-keyed every order twice, roughly 22 hours/month total, and 6 to 8 orders/month shipped with a wrong address or reference.
He commissioned a standard real-time connector at 26,000 EUR, delivered in 8 weeks, with maintenance at 500 EUR/month. Result: double entry disappears (22 h/month recovered, valued at 32 EUR/h fully loaded = 704 EUR/month), and order errors drop 45%, avoiding roughly 1,600 EUR/month in returns and credit notes. Net monthly gain: ~2,300 EUR. The investment is repaid in about 12 months, maintenance included.
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FAQ
Do I really need real-time sync?
No. A nightly batch sync is enough for many SMEs and costs 30-40% less. Real time is justified when sales and logistics teams work on the same orders at the same time.
What happens when the CRM API changes?
That is exactly what maintenance covers. Vendors like Salesforce and HubSpot publish API versions with notice; a 350-800 EUR/month budget covers connector updates with no surprise invoice.
Can we start with a no-code tool like Zapier or Make?
For a few hundred operations/month, yes, at 20-100 EUR/month. Beyond high volumes or complex business rules, per-volume cost and technical limits make a custom connector more economical.
How long until I see ROI?
Most SMEs break even in 8 to 14 months thanks to saved entry hours and fewer errors. The higher the order volume, the faster the return.
Who owns the connector code?
With Kolonell, the source code is yours on delivery. You are not locked into a vendor or a proprietary subscription.
Let's scope your project. Tell us your two tools (ERP + CRM), monthly order volume, and objects to sync, and we will scope a connector between 18,000 and 45,000 EUR. 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.
