Preparation for and attendance at tax audits and external audits

Preparation for a tax audit

The tax audit (also known as an external audit) is rightfully feared. Apart from a tax fraud investigation, this represents the most robust invasion of a client's domain by the tax authorities. Thanks to the future-oriented consultancy services of our experienced tax experts (namely, preparation for a tax audit), we have already "taken the fear" out of many a tax audit, and worked closely with our clients to develop strategies so that they are better prepared to answer the many questions posed by the external auditor.

Attendance at contentious external audits

If problems arise during an ongoing external audit, we will attend the contentious audit (for example, defence of estimates). If an audit is pending, we will try to handle this audit in our consultancy firm so that you are not placed under any undue pressure.

Contact persons at KONLUS for tax audits:

Fields of activity:

  • Strategic advice in advance of using the latest audit software
  • Expert clarification of problematic audit tasks
  • Representation during the tax audit and in the final discussion of the tax audit with a tactical focus on possible appeal procedures
  • Defence of estimates in an external audit
  • Evaluation of the audit report and a tax burden comparison


Digital audit (GDPdU) - on an equal footing with the tax office - audit simulation

The digital audit is becoming a standard auditing tool. We can assist you or your company during a tax audit. The tax authorities use the WinIDEA auditing software, which was developed by Audicon. In addition to WinIDEA, we, at KONLUS, also use other auditing software (for example, ACL and InfoZoom) and provide this service and our auditing expertise in this area to our clients and professional colleagues. The use of other software enables us to identify "weaknesses" during a WinIDEA audit. Upon request, we work under a client protection agreement or without appearing visible to the outside world. As an auditor, have you adhered to the principles of computer-based bookkeeping (GoBS), the relevant auditing standards (IDW PS330) and the generally accepted accounting principles when using information technology (IDW RS FAIT 1)? Have you audited your client's IT systems?

It is not just a matter of acquiring the relevant software. To use it, you also need experience in the relevant audit areas, which, in turn, depends on the type of company. 

These programs have the following features:

  • Custom data views
  • Data analysis
  • Comparative statistics (for example, the chi-square test and distribution in accordance with Benford's Law)
  • Analysis of multiple assignments
  • Gap analyses
  • Summation and age structure analyses
  • Exception and anomaly searches with simple and complex criteria
  • Costing functions
  • File comparisons
  • Various arbitration processes.

After performing the relevant audits and analyses, we work with you to develop appropriate defence strategies through to a voluntary disclosure (to avoid penalty) in the event of tax evasion. The findings of an audit are not only tax-relevant but also business-relevant. The aforementioned audits can detect, with high probability, accidental errors as well as deliberate manipulations (for example, by employees). In addition to preparing for a tax audit, digital auditing also increases corporate security.


We provide the majority of our tax consultancy services, in particular, tax audits to clients in Bergisch Gladbach, Cologne, Leverkusen, Gummersbach, Bonn, Düsseldorf, Remscheid, Solingen, Wuppertal and neighbouring regions. However, we also operate throughout Germany. Our branch office is located in Berlin.


Schloss-Straße 20
51429 Bergisch Gladbach
Tel.: +49 (0) 22 04 / 9 50 81 00
Fax: +49 (0) 22 04 / 9 50 81 10

Service Hotline

+49 2204 9 50 81 00


Im Mediapark 5a
50670 Köln
Tel.: +49 (0) 221 / 95 26 81 - 170
Fax: +49 (0) 221 / 95 26 81 - 113

External audit & tax audit tax office | Cologne & Berlin