CRM and ERP integration over API interfaces
We connect your CRM with ERP, accounting and internal systems – via a native connector, middleware like n8n or a custom API. Bidirectional data sync instead of CSV exports and copy-paste.
Three ways to connect your CRM
Every CRM or ERP integration ends up running through one of three routes: a ready-made connector from the marketplace, middleware like n8n that translates between systems, or a custom API for cases no standard covers. The real work isn't in the code – it's in the question of which route fits your fields, your volume and your budget.
We settle that before building, map the fields cleanly and ship an interface with error handling, retry logic and monitoring – so it still runs in six months. For the HubSpot-specific details – which objects can be connected and where the marketplace limits are – the guide on HubSpot interfaces helps. Not sure whether your CRM setup is even ready for it? Then CRM consulting is the earlier step.
- What is a CRM API integration?
- A CRM API integration connects your CRM through its programming interface directly with other systems like ERP, accounting or shop. Contacts, orders and statuses flow automatically between systems – one way or bidirectionally – instead of being exported and imported by hand. That way every tool holds the same data.
Integrating an ERP via API: which fields actually flow
With an ERP integration, the route depends on the ERP system. SAP, Microsoft Dynamics, Lexoffice, Xentral or JTL-Wawi each bring their own REST API or webhook mechanism – some cleanly documented, some idiosyncratic. Over that interface the records travel both ways: orders, invoices and customer master data from the ERP into the CRM, new contacts and deals from the CRM back into the ERP. The effort is in mapping the fields, not in setting up the connection.
For a plain CRM API integration a standard connector is often enough. Once an ERP with its own field logic or document-numbering scheme is involved, the route usually runs through middleware like n8n or a custom interface. Whether your CRM is even clean enough for the connection is settled up front by a CRM audit.
Example interface: ERP ↔ HubSpot
Sample- Direction
- bidirectional (ERP ↔ CRM)
- Trigger
- webhook on a new order + nightly full sync (02:00)
- Mapped fields
- customer number, company name, order value, payment status (4 core fields)
- Volume in this example
- ~300 orders per month
- Error handling
- 3 retries, email alert on failure
- Build time
- 1–2 weeks to live
A sample of a typical connection for orientation. The concrete fields, frequencies and volume are set during mapping – depending on your ERP and your processes.
Connector, middleware or custom API?
The three routes side by side. The right one depends on how special your fields and processes are – not on what costs the most.
If the data flow runs through n8n, we set it up and operate it too – as your n8n agency.
HubSpot's API works without an Enterprise licence – reading and writing contacts and deals is possible with a Private App on the free tier. Where the limits are is explained in the post on free HubSpot CRM API access.
What manual reconciliation really costs
Send me the systems you want to connect – I'll tell you honestly whether a connector is enough or it needs a custom interface.
Typical connections from practice
A few cases that come up again and again. The logic is similar everywhere, the details never are.
ERP ↔ CRM
Orders and customer master data from the ERP land in the CRM, deals flow back into the ERP. Both sides stay on the same footing without anyone typing.
Accounting & billing
Invoice and payment status from Stripe, FastBill or Lexoffice flow into the CRM – sales instantly sees who has paid and who hasn't.
Shop & orders
Orders from the online shop create or update contacts and deals in the CRM, including cart and order history.
Custom database & tools
Internal databases or industry software without a ready-made connector we hook up over the REST API or webhooks.
Working with HubSpot and n8n? The technical side is covered in the guide on the n8n HubSpot integration. What a real connection with data enrichment looks like is shown in the CRM data enrichment case study.
How we build your interface
From taking stock to ongoing monitoring – structured and without an endless project.
Which systems are in play, where do data flow by hand today, which fields really need to stay in sync? The result is a data-flow diagram, not a wish list.
Is a native connector enough, do you need middleware like n8n, or a custom interface? That decision is made before the first line of code, not after.
Map fields between systems, define transformation rules, set up deduplication and validation logic. This is where it's decided whether the data ends up clean.
API connection, webhooks or middleware flows – with authentication, error handling, retry logic and logging. Bidirectional wherever the process needs it.
Every data flow is checked with real test data before it touches your production systems. No risk to your live data.
Alerting on errors, technical documentation and a runbook for your team. Optionally, we handle ongoing maintenance on a retainer.
Honestly: when a connector is enough and when it isn't
A native connector is enough
- You connect two standard systems with standard fields
- The sync may run one way
- There's a maintained connector for exactly your tools
- The data volume is manageable
A custom interface makes sense
- You need bidirectional sync with custom logic
- Fields or objects are missing from the standard connector
- Several systems should run through one central place
- The data has to demonstrably stay on an EU server
Common questions about CRM and ERP integration
Short and concrete – so you quickly know how we work.
Book a free intro call
We'll clarify which systems you want to connect, which route fits and roughly what the interface will cost.
Pick a time →Related services
Services that are often booked together.
Let's connect your systems
Tell us briefly which systems you want to connect – we'll get back to you quickly with a clear next step.
- Free intro call (15–20 min)
- A clear read on feasibility and effort
- A recommendation on which route fits your case