A short Information in English Language

What is OpenImmo ?

OpenImmo describes real estate objects in a set of app. 300 fields.
In the Versions 1.1 to 1.2.7 it uses the XML Data Format so it can transport all languages using UTF-8.
A new version using REST-API and JSON is on its way.
Objects are describes in categuries:
- object categories like house, appartment, condo, business office, store etc.
- the way of marketing: buy, rent, lease -
- geografic information line street, zip-code, place ..
- price information for buying and renting, several costs and real-estate-agent fees ...
- information about the square of living, storage, balconi ...
- features in livingroom, bath, house or commercial properties
- technical information about heating, cooling, networks ...
- conditions as the state of renovation
- administration of the building or space
- free text areas
- attachments für images, pdf, video an others
- contact information of the real estate agent - and a group of "user_defined_extend" fields allow partners the describe and transfer infomation that can not be found in the other fields.

In most cases openimmo data is send as a ZIP-Packed file (Including binary data) by a software product to an online marketing or service portal. The transfer is mainly done using the FTP protokoll.
- User request can be sent form portals back to software tools as an XML Feedback Attachment in an E-Mail.

Who is behind the OpenImmo Group

The OpenImmo Group was founded in 2002 as a german initiative to build a single data standard to exchange real estate data. It has now ( Jan. 2022) about 35 supporting members, over 450 licence holders, and more the 15.000 users at all.
See the list of supporting members and licence takers on the german website.
The group is organiced as a non profit association under german law.

Who uses OpenImmo
The standard has has started in the german speaking Europe since 2002. Now a lot of other countrys denmark, netherlands, belgium, france or luxemburg cooperate with german software vendors or portals. Countys like ungary, italy, spain an others are linked often through vacation rentals and buying processes.

The XML Version

The version 1.0 was designed in 2002 unsing the XML Format, which was the right style at that time. Between 2003 and 2017 seveal updates were developed. The focus was always on a high compatibility to older versions. Data is mostly packed together with binary data into a ZIP file and then transfered form sender (realtor softwas ) to the receiver (online portal).
The current (2019) version 1.2.7 can be downloaded from the german website. The element names an comments are in german language.

OpenImmo Translation
There will not be a pure english version in the near future. But we provide a translation of the fieldnames in english. This is available for individuals or companys who get a licence key. This includes a registration key to use in the openimmo data. You can order the license here for a one time fee of 100 Euro (No VAT applys) from the german Website.


In 2015 the OpenImmo Group startet the planung process for a new and no more compatible version 2.x using a REST-API. The data structures have been reviewed and the amount of elements have been reduced and updated.
At the end of 2021, the last "Beta" Version of OpenImmo 2.x has been finished.
The final Version 2.0 ist planed to be released in mid 2022.

FAQ's for Version 1.x

Here are some of the most asked questions.
First an most important:

Is OpenImmo free of charge?
Yes, because there are no general fees. In the license conditions of version 1.2, however, a one-time processing fee of 100 Eur is charged for the granting of a user ID for commercial use. However, if you want to advertise using OpenImmo, this is only permitted if you are a member of OpenImmo e.V. or a licensee. Who e.g. publishes only the data on a broker homepage does not need one! License.
Do I have to become a member of the OpenImmo e.V.?
No, as described under point 1, this is not absolutely necessary. The advantage of a membership is the advertising effect and the possibility to help shape the development. More and more brokers are looking for OpenImmo compatible software. Also OpenImmo using portals enjoy higher popularity, because the data transfer to them is easier. In addition, it is possible for members to make suggestions for new versions.
Why do I need to register to download?
So that we can inform you of any changes to the standard or the terms of use.
Do I have to transfer all data to OpenImmo?
No. In total, there are about 300 possible entries. The large number was chosen to meet the most diverse requirements. This way you can easily offer a holiday home for rent, enter all costs and ancillary costs and also describe the distance to the beach or tennis court. Only about 15 fields are mandatory.
Does OpenImmo have anything to do with the transmission?
A clear No. OpenImmo only describes the dataformat you/your software uses. With OpenImmo it is not determined to whom a software sends data. OI has no influence whatsoever on the business relationships between the companies or persons involved. OpenImmo does not play an active role in the production, transmission or distribution of data. This is the sole responsibility of the users sending or receiving the data. The data is also not sent via the OpenImmo Website.
What does a realtor have to do?
On the one hand he must have an OpenImmo compatible software. A list of possible companies can be found in the member list. In most cases, the necessary transfer data can be set in the software.
What must a "sending" software company do?
You need to create OpenImmo records from your software. This can be done via simple string functions or via special XML interfaces. Alternatively, conversion via an XSLT script is possible.
What does an online portal have to do?
Roughly speaking you need to be able to import the XML data from OpenImmo. This can be done manually or through additional scripts. In the paid support package you will find examples for the programming language PHP. Of course, you also need to provide a way to get the data to you. Mostly the FTP protocol is used here.
(Translated with the help of www.DeepL.com/Translator from Cologne)