Our fields of expertise


For years, cum/ex trades have been the subject of press coverage and increasingly public prosecutors’ offices and courts in Germany and abroad. In this context, the term Cum/Ex is often misleadingly used also for other tax-motivated trading strategies (such as tax arbitrage by means of Cum/Cum transactions as well as via trading in dividend coupons, ADRs, GDRs, fund shares, etc.). This often results in a blanket prejudgement of trading activities without concrete examination of the individual case. As a result, the parties involved are exposed to increased public pressure to prosecute, which is exploited by the investigating authorities with hasty accusations, up to and including immediate searches of business and private premises.

Whether it is a matter of verifying tax post-declaration obligations (§ 153 AO), defending against accusations of tax evasion (§ 370 AO or 378 AO), or avoiding reputational risks, a comprehensive clarification of the facts is necessary. The clarification is followed by a precise legal assessment. In addition, Heist Legal can offer economic expertise in order to distinguish problematic transactions from regular economic activity. In this way, risks can be identified proactively and at an early stage, and existing allegations can be dealt with in a qualified manner.

The evaluation of transactions requires in-depth knowledge of the financial market, especially with regard to technical processing and the relevant tax law. Due to many years of dealing with this special matter on behalf of authorities and financial institutions, Heist Legal is in a position to forensically process, reliably assess and legally evaluate the relevant facts.


Heist Legal pursues a risk-based approach. First, we identify core risks to your company, based on which we then implement measures within the Compliance Management System. We evaluate existing compliance structures and supplement them cost-effectively.

Regular training as well as recurring reviews of the measures that have been taken to ensure the system’s sustainability and help avoid liability risks.

Heist Legal furthermore assists executives and persons responsible for compliance in the private sector as well as management bodies of authorities, providing consultation on how to minimise the risk of liabilities for associations as well as personal liability risks.

Internal investigations

If companies or authorities suspect misconduct among their employees or members of management, Heist Legal investigates the matter in a targeted manner and presents possible courses of action. As we accompany the process, we consider various aspects, including the liability of board members, regulatory breaches, reporting obligations as well as the threat of asset recovery.

In the course of this, we focus on processes that are relevant under commercial law and criminal law on tax matters, particularly in the financial services sector. We draw on our years of experience in the sector to analyse elaborate and complex matters. On request, Heist Legal uses IT forensics to process large quantities of data; we also cooperate with expert partners in the fields of auditing and IT security.

Besides conducting independent, event-related investigations, Heist Legal also offers plausibility checks on the results of investigations conducted by third parties and compiles second opinions.

Identification of possible liability risks

Heist Legal reviews possible liability risks for companies and their members of management, both as part of internal investigations and on a separate request. Risks may include obligations to file subsequent tax declarations, penalties, liabilities in tort as well as obligations to establish provisions.

Based on the results of these reviews, we develop approaches that take specific, regulatory requirements and the economic options of the respective business into account. On request, we coordinate closely with responsible parties both within the company and without, including legal, tax, regulatory and auditing departments and authorities.

Individual criminal defence

At Heist Legal, individual criminal defence in the fields of commercial law and criminal law on tax matters is one of our areas of expertise. For us, defence begins at an early stage, during the preliminary proceedings, as this is when the foundation for the further procedure is laid. Our services include assisting persons concerned during searches and similar measures and in dealing with threats created by the media.

Through all of this, we strive towards integrity, which in turn gives us the necessary sensibility when dealing with investigating authorities. If a case comes to trial, our dedicated barristers represent our clients across all instances.