This is the first article in a guide that walks you through the process of connecting Moss and DATEV Direct.
Follow this guide step by step to successfully connect Moss and DATEV Rechnungswesen.
Note: There are two different DATEV integrations in Moss. If you want to connect Moss with DATEV Unternehmen Online (DUO), you can find the relevant guide here.
The purpose of this article
This article guides you through the steps you need to take to prepare the connection between the DATEV Direct Integration and Moss.
To synchronise data between Moss and DATEV Rechnungswesen directly without any intermediary system we require certain information from you and a number of prerequisites must be met. These details and decisions are essential for establishing the connection later on.
The DATEV Direct integration connects Moss directly to DATEV Rechnungswesen—that is, to the actual DATEV accounting server where your financial accounting takes place.
Unlike traditional DATEV cloud integrations, there is no upstream tool and no intermediate step via DATEV Unternehmen Online. Instead, Moss synchronises accounts, suppliers, and postings directly with DATEV Rechnungswesen.
This ensures that both systems continuously operate on the same data, and postings are transferred straight into DATEV batch processing without any media breaks.
Important: Clarify legal responsibility first
Since this integration connects directly to a DATEV server, it is essential to clarify who is legally responsible for that server.
Depending on your setup, this may be:
the client (i.e. your company), or
a tax advisor firm that operates or pays for the DATEV server.
This information is crucial since the legal owner:
must approve access to the DATEV server, and
determines the further setup process.
Before starting the setup, you should clarify who owns the DATEV server and which advisor and client numbers are assigned to it.
The DATEV Direct integration can only be successfully set up if this information is provided.
DATEV Direct Integration – Preparation & Prerequisites
This guide helps you prepare DATEV Direct in Moss before starting the actual setup.
A proper preparation is essential: DATEV Direct connects Moss directly to DATEV Rechnungswesen, the actual accounting server. To ensure the connection can be established smoothly, certain information must be clarified and be available in advance.
Overview: What to clarify before you start
Before beginning the setup in Moss, make sure you can clearly answer the following questions:
Who is the legal owner of the DATEV server?
Which advisor number is linked to the DATEV database?
Which client number should be connected?
Where is the DATEV server technically hosted (e.g. SmartIT, DATEVasp, tax advisor firm, IT partner)?
This information determines how the setup will proceed and who must legally approve the integration.
Why this preparation is important
DATEV Direct is not a simple export interface. Moss connects directly to DATEV Rechnungswesen.
If any of the key details are incorrect, the connection may:
fail to be established, or
only be activated with delays and additional clarification.
Careful preparation saves time and helps avoid unnecessary interruptions during the setup.
The three critical pieces of information in detail
1. Legal owner of the DATEV server
The legal owner is the organisation that is responsible for the DATEV server and bears the associated costs.
This is not necessarily the same company that you are connecting with Moss.
Typical scenarios:
Your company operates the server itself, pays for DATEV SmartIT / DATEVasp directly, or is a customer of a DATEV IT partner.
Your tax advisor firm operates or pays for the DATEV server, either through an IT partner or directly provided by DATEV.
This information is crucial because the legal owner:
must grant legal approval for the integration, and
may trigger additional setup steps in certain cases.
2. Advisor number (absolutely critical)
The advisor number must exactly match the number under which the DATEV database is maintained.
Especially important:
With DATEV SmartIT, there is often a so-called client-specific advisor number.
This exact advisor number must be entered in Moss.
An incorrectly stored advisor number is one of the most common reasons for failed connections.
3. Client number
The client number determines which DATEV client is connected to Moss.
Please note:
The client number must match the selected advisor number.
In most cases, this is the primary client number of your company.
Incorrect details at this stage will prevent the connection from being successfully established.
How to find the correct information
The most reliable source for all relevant details is your DATEV invoice.
On DATEV invoices (e.g. for SmartIT or DATEVasp), you will find:
The invoice recipient (server owner)
The advisor number used
The corresponding client number
Information about the hosting type (SmartIT, DATEVasp, etc.)
Alternatively, you can contact:
Your internal DATEV or IT administration
Your tax advisor firm
Your DATEV or IT partner
If you are unsure about any of these points, clarify them before starting the setup. This will save time and avoid follow-up questions later.
What you should have ready before setup
Before starting the setup in Moss, make sure you have the following information available:
Legal name of the DATEV server owner
Advisor number of the DATEV database
Client number to be connected
Type of IT infrastructure (e.g. DATEV SmartIT, DATEVasp, tax advisor firm, IT partner)
Email address of a contact person for the setup
With this information, you are fully prepared to proceed with setting up the DATEV Direct integration in Moss.
You have now reached the end of the preparation. Make sure you meet all the requirements listed above and have the necessary information ready.
In the next article, we’ll guide you step by step through setting up the DATEV Direct integration in Moss and highlight what to pay attention to during the setup process.