Getting a German property in front of buyers or tenants means putting its data on portals. There are two established ways to do that, and they work very differently. One is OpenImmo, an open industry file format that most German portals accept. The other is the ImmobilienScout24 REST API, a proprietary interface that talks to a single portal. This guide compares them on coverage, update model, media handling, and effort, and shows how a system of record ties both back to one property record.
OpenImmo: one file format, many portals
OpenImmo is an XML standard for German real-estate data, maintained by the OpenImmo initiative. REPM exports OpenImmo 1.2.7. The idea is simple: you describe a property once in a structured XML document, wrap it together with its photos and documents in a ZIP package, and drop that package into a portal's transfer folder, usually over FTP or SFTP. The portal picks the package up on its own schedule and ingests it.
Because it is an open standard, the same export reaches many destinations. Portals such as Immowelt and Immonet, plus dozens of smaller regional and specialist sites, read OpenImmo. That is the format's biggest strength: build the export once, and each new portal is mostly a matter of adding transfer credentials, not writing new code.
OpenImmo carries create, change, and delete instructions through an action flag on each property, and supports both full imports, where the package is the complete truth, and partial imports that send only what changed. Media travels inside the package: images and attachments are files in the ZIP, referenced from the XML, with the cover image and ordering expressed in the document. One package, everything in it.
The ImmobilienScout24 API: real-time, one portal
ImmobilienScout24 is Germany's largest property portal, and it offers a proprietary REST API alongside file import. REPM ships an ImmobilienScout24 connector that speaks it. Instead of dropping a file, the connector makes direct calls: authenticate over OAuth, create or update a listing, upload each photo through a separate attachment call, then publish. Because it is request and response, a change lands in near real-time rather than at the next import cycle.
The trade is scope. The API only reaches IS24. It also asks more of the integration up front: an application registration, API access approval, token handling, and respect for rate limits. In return you get tighter control, immediate publish and unpublish, and structured data flowing back, including contact inquiries.
Side by side
| OpenImmo 1.2.7 | ImmobilienScout24 API | |
|---|---|---|
| Coverage | Most German portals (Immowelt, Immonet, many more) | IS24 only |
| Update model | Batch: package dropped in a transfer folder, ingested on the portal's schedule | Real-time: direct per-listing calls, near-instant publish and update |
| Media | Bundled inside the ZIP, referenced from the XML | Uploaded via separate attachment calls |
| Effort | Build once, add credentials per portal | Per-portal integration, OAuth, rate limits |
| Lead return | Depends on the portal | Inquiries retrievable via the API |
You do not have to choose
In practice the two are complementary, not rivals. OpenImmo gives you breadth cheaply: one export, many portals. The IS24 API gives you depth on the portal that produces the most demand: real-time control and a clean path for inquiries to come back. Most German operators run both, and that is exactly what REPM does out of the box, so you publish to the wide OpenImmo network and to IS24 from the same property.
The point of a system of record: leads back to the unit
Syndication is only half the loop. The value shows up when a reply from a portal lands back on the right property, not in a shared inbox. REPM's integrations return matched leads to the unit: inquiries are de-duplicated, consent is logged, and search-profile matching makes sure no prospect is contacted twice for the same thing. From there the same record drives your lease and tenant management once a deal closes, and your development cost cockpit while the asset is still being built.
Because it all sits on one property record, the web expose you tracked, the lead that answered it, the lease you signed, and the DIN 276 budget you are spending are the same object seen from different angles, not four disconnected tools you reconcile by hand.
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FAQ
Do I need both OpenImmo and the ImmoScout24 API?
No, but most operators use both. OpenImmo reaches many portals with a single export; the ImmoScout24 API adds real-time control and inquiry return on Germany's largest portal. REPM supports both from one property record.
Does ImmobilienScout24 also accept OpenImmo files?
Yes, IS24 accepts OpenImmo import as well, but its proprietary REST API gives finer, real-time control and structured lead retrieval that the file route does not.
How does the OpenImmo transfer actually work?
You export a ZIP that contains the OpenImmo XML plus the photos and documents, then place it in the portal's FTP or SFTP transfer folder. The portal imports it on its own schedule.
What happens to a portal inquiry in REPM?
It is returned matched to the unit, de-duplicated, and logged with consent, then matched against search profiles so the same prospect is not contacted twice.