DATEV Cloud & Client Base

In tax firms, the client base often grows over decades. New mandates come in, firms merge, legal forms change, clients get created more than once. As long as operations run locally, this usually stays manageable, even if it is tedious.

With the upcoming move to DATEV cloud applications, this changes fundamentally. What used to „somehow work" now has to be unambiguous, consistent and machine-readable.

That turns the client base from a background topic into the decisive success factor of the migration.

Why client consolidation is now a strategic topic

1. Historically grown data is the norm

In practice, we regularly see the following in larger firms:

the same client created more than once
different client numbers for different legal forms
parallel master data from earlier firm structures
inconsistent spellings, addresses and assignments

From a professional point of view, much of this is understandable. Technically, however, it means that DATEV „sees" the same people or companies more than once.

As long as data is maintained locally, you can deal with it. In the cloud, however, this leads to: faulty transfers, duplicate or contradictory master data, high manual rework effort and risks in reporting.

2. DATEV migrates data, but not firm logic

DATEV provides tools and migration paths for the move to the cloud. What DATEV cannot do:

professionally merging historical clients
assessing duplicates or similar clients
deciding which client number is „leading"
dissolving legacy structures from mergers

These decisions always rest with the firm.

The typical mistake: „we will clean that up later"

Many firms keep putting the topic off because:

day-to-day operations take priority
no one knows exactly how big the problem is
nobody wants to make risky changes in DATEV

The problem with that: after the migration, cleaning up does not get easier, it gets significantly more expensive. By then the data is already in the cloud, processes are built on it and corrections come with a higher coordination effort.

The right approach: structured preparation instead of a permanent manual building site

A proven path is to clean up the client structure in a targeted way before the DATEV cloud migration, without disrupting day-to-day operations.

The basic idea is simple: the machine does the legwork, the firm makes the professional decisions.

The technical process, explained clearly

1. Reviewing the client master data

First, relevant client master data is exported (e.g. name, address, tax number). There is no access to ongoing bookkeeping and no intervention in DATEV production systems.

Goal: all clients are available in a comparable, neutral structure.

2. Automatic detection of possible duplicates

On this basis, clients are identified that:

have identical or very similar master data
use the same tax number or VAT ID
probably belong together despite different spellings

This is not about decisions, but about flagging anomalies.

3. Reasoned preliminary assessment

Each detected case is rated: „very likely the same client", „possible, please check", or „probably not the same client".

Important: every assessment comes with a traceable justification (e.g. same numbers, same address, high similarity).

4. Grouping clients that belong together

Often it does not concern just two records, but whole groups: several client numbers, several legal forms, different time periods. These are presented as client groups that belong together.

5. Professional decision by the firm

The firm receives a clear review list:

Which clients should be merged?
Which should not?
Where is clarification needed?

The professional decision remains entirely with the firm.

Conclusion

The DATEV cloud migration is more than an IT project. It is the moment when historically grown structures meet modern requirements.

Those who systematically clean up their client base before the migration save:

time during the migration
costs for rework
risks to compliance and data quality

The best preparation is structured groundwork.