Proficient. Trustworthy. Custom-made.

COTAXX Treuhand Steuerberatungsgesellschaft mbH headquarters is located in the center of Berlin with an additional branch in Stuttgart.

It is our aim, to develop together with our clients, competent tax and business concepts that are individually tailored to their needs, visions and ideas.

In addition to the traditional consulting fields we also offer comprehensive tax and business guidance as well as support in international affairs.

Our employees are experienced tax advisors, consultants specialized in international tax law and managerial accountants. Many years of experience, continuous professional training and personal integrity is a guarantee for the professional advice, quality and discretion that we provide.

We look forward to your contact via phone, email or your personal appearance in our firm.


Diplom-Kauffrau Carola Schumacher
Certified Advisor in International Taxation
Tax Consultant

Dipl.-Kffr. Carola Schumacher
  • Studied Business and Management in Bonn / Berlin
  • Graduated in 1987 with degree in Business and Management
  • 1987 – 1992 Research Associate at the Institute of Auditing and Trust Services
  • Employed in a mid-sized tax consultant company
  • 1995 Concluded tax advisor exam
  • Since 1994 I have successfully owned my tax advisor practice
  • 2012 Certified Tax Advisor for International Tax Law
  • 2015 Marked 20th anniversary as a tax advisory professional
  • 2015 Managing Director of COTAXX Treuhand Steuerberatungsgesellschaft mbH Berlin / Stuttgart

Diplom-Kauffrau Johanna Müller
Certified Advisor in International Taxation
Tax Consultant

Dipl.-Kffr. Johanna Mueller
  • Studied Business and Management at Ludwig-Maximilian University in Munich
  • Graduated in 1985 with degree in Business and Management
  • 1990 Appointed as tax advisor in Stuttgart
  • 1990 – 2000 Employed at various national and international tax advisories and chartered accountant associations in Munich, Stuttgart and Mannheim as a tax advisor and head auditor for medium-sized enterprises
  • 2012 Certified Tax Advisor for International Tax Law
  • 2015 Marked 25th anniversary as a tax advisory professional
  • 2015 Managing Director of COTAXX Treuhand Steuerberatungsgesellschaft mbH Berlin / Stuttgart

In that we have been consulting companies, entrepreneurs and individuals for more than 25 years we are able to fall back on the wealth of experience and knowledge gained within this time period. With a team of tax advisors, accountants and tax clerks we would gladly support you in the following:

  • Preparation of the tax declaration for companies of all legal forms
  • Preparation of the tax declaration for private individuals
  • Consultation and support with legal form selection or change of legal form
  • Investigation and comparison of the tax burden
  • Creation of commercial and tax financial statements
  • Annual financial statements according to IFRS
  • Consultation of national and international concepts
  • Preparation of tax assessments
  • Review of tax assessments accuracy
  • Submittal of appeals
  • Representation in dealing with tax authorities
  • Support during company audits

 overview of practice areas

Annual Financial Statements and Tax Returns

We create for individuals as well as for companies of all legal forms the annual financial statement and tax declaration, for example:

  • Creation of the annual statements for clients in all legal forms
  • Disclosure of annual statements for the Federal Gazette
  • Creation of ascertainment of profits according to German paragraph §4 Abs. 3 EStG for clients not required to file a statement
  • Consultation regarding accounting and evaluation
  • Create cost estimates and cost accounting
  • Analyze income to assets ratio
  • Submission of formulation proposals for the drafting of the annex or the annual report for corporations
  • Ensuring the exploitation of all tax savings opportunities
  • Yearly financial reports according to the IFRS
  • Consultation regarding national and international concepts

 overview of practice areas

Payroll and Financial Accounting

Financial accounting is the foundation of business decisions and the basis for the creation of annual financial statements and tax returns.

In our view it is important to tailor the accounting to your needs and that our evaluations are both understandable and significant for your purposes.

Your accounts can be processed with us on a monthly, quarterly or also annual basis. Provided that you create the accounts in your company yourself, with your own software or via DATEV access, we will gladly support you with:

  • Creation of financial accounting in accordance with the legal requirements
  • Business evaluations
  • Creation of outstanding payments lists
  • Advance VAT return
  • Applications for permanent extension for VAT return
  • Account coordination
  • Preparation of cost calculations

Payroll Accounting

  • Preparation of the complete payroll in accordance with the legal requirements
  • Payroll tax notification
  • Preparation of the social security notifications
  • Statement of earnings
  • Applications for continued payment of wages
  • Applications for maternity allowances
  • Social security audits

 overview of practice areas

Business Consultation

You have successfully positioned your business in the market, but where will it be in five years?

We can illustrate with a goal-oriented analysis whether your investment is optimally positioned for the future. In this case fiscal and business issues are so closely intertwined that a fiscal concept is not possible without economic consultation.

  • Costs, profitability and liquidity calculation
  • Definition of investment, financing and dividend policy
  • Business startup consultation, legal form and selection of location
  • Bank discussion preparation and support
  • Succession planning
  • Preparation of cost calculations
  • Cost management in small and medium-sized enterprises

 overview of practice areas

International Tax Law

International tax law is becoming increasingly important. In today’s world private as well as economic relationships no longer end at borders of any particular country. Nonetheless, the tax authority is still focused on the state borders, even if the trend towards harmonization of fiscal tax law within the European Union is beginning to emerge. Nevertheless, the differences themselves within the EU are so large that a proper fiscal tax structure planning is essential. This is particularly true of relations with countries outside the European Union.

We have been working for years with our international colleagues in order to avoid double taxation and to better coordinate international cases.

As expert advisors for international tax law we counsel internationally operating individuals for the following:

  • Inquiries regarding double-taxation
  • Preparation of tax returns for foreign income
  • Preparation of tax returns for persons with limited taxable income
  • International inheritance law
  • Immigration to or emigration from Germany
  • Advising an internationally active artist
  • Refund or crediting of foreign investment income

Consultation of internationally operating companies focuses mainly on:

  • Questions concerning the application of the double taxation agreement
  • International tax planning
  • Choice of legal structure
  • Overseas deployment of employees
  • Foundation of permanent establishments
  • Consultation for tax optimization real estate acquisitions in Germany
  • Consultation on sales tax affairs

 overview of practice areas

Consultation for Startup Companies and Entrepreneurs

One primary focus of our work is consulting start-ups and entrepreneurs. In particular, we have many years of practical experience and insight on how to properly apply for KfW funding.

  • Startup consultation
  • Advice on legal structure
  • Professional assessment of the likelihood of success for startups
  • Financing consultation
  • Creation of profitability forecast, liquidity planning and investment calculations
  • Assistance in the preparation of business plans
  • Advice and support in negotiations with institutions, banks etc.


Here you will find useful information, working documents, and checklists grouped according to the respective themes.

Job Posting

If you want to apply for a job in our offices, take a look at our german page

You can contact us at:

Central Berlin

Dipl.-Kffr. Carola Schumacher
Fachberaterin für internationales Steuerrecht, Steuerberaterin
Schlesische Str. 38
10997 Berlin - Kreuzberg

T +49 30 80936899
F +49 30 614 03 569

Office hours
Monday to Thursday 8 a.m. to 5 p.m.
Friday 8 a.m. to 2 p.m.

Travelling with public transportation
U1 Schlesisches Tor

Branch Stuttgart

Dipl.-Kffr. Johanna Müller
Fachberaterin für internationales Steuerrecht, Steuerberaterin
Schulze-Delitzsch-Strasse 38
70565 Stuttgart

T +49 711 12278036

Office hours
Monday to Thursday 8 a.m. to 5 p.m.
Friday 8 a.m. to 2 p.m.

Travelling with public transportation
Underground station Lapp Kabel (Line U12)