IAM Patent 1000 (2024)

GEISTWERT is top of the class for patent litigation in Austria. Although domestic and international clients in the life sciences account for most of the workload, the practice is also approached by leading figures in the electronics and mechanics fields. Recently Constantin Kletzer, Rainer Schultes and Alexander Schnider have been representing Teletan in an infringement case regarding the patented authentication system on its online payment authorisation platform. “Constantin is one of the best IP lawyers in Austria. He has an incredible knowledge of patent matters, and he is both fast and reliable.” “Rainer is direct, clever and always prepared”; and “Alexander delivers rock-solid advice in a very enjoyable and educational manner”. Completing the line-up, Juliane Messner and Max Mosing effortlessly handle complex contracts. Together they have been working with IPAG, a Universities Austria project in which Austrian universities and companies created a set of model agreements to assist the effective transfer of knowledge and technology. Austrian universities and businesses collaborate to create standard contracts, which are then evaluated and commented on by legal professionals.

Legal 500 Intellectual Property (2024)

The ‘knowledgeable and experienced’ team at GEISTWERT, consisting of Constantin Kletzer, Juliane Messner, Max Mosing and Rainer Schultes covers the full range of IP matters, assisting both national and international clients with the management of their portfolios and filings, while frequently acting in disputes concerning infringements, cancellation and opposition proceedings. The practice also routinely advises on the transfer of IP rights tied to transactions, including conducting due diligence checks. The firm maintains a broad client base, with the food and beverage and automotive sectors driving a significant percentage of the firm’s work, in addition to its strong niche in the video game industry.


‘I have been working with Constantin Kletzer for many years. He is always attentive to clients’ needs and is able to find practical and efficient solutions, especially when cases are complex.’

‘GEISTWERT offers a fast service for all questions relating to IP, the orientation is customer-friendly and pragmatic and the skills of the lawyers are completely convincing.’

‘Constantin Kletzer has a pragmatic approach to given issues, works in a results-oriented manner and finds creative solutions that go outside the box.’

Legal 500 TMT (2024)

GEISTWERT‘s all-partner team, consisting of Constantin Kletzer, Juliane Messner, Max Mosing, Alexander Schnider and Rainer Schultes, assists TMT clients, including social media and streaming giants, on a spectrum of IT and IP matters, and maintains a particularly strong presence in Austria’s video game industry, where it advises clients on matters ranging from copyrights to NFTs. The team supports clients engaged in IT upgrade and outsourcing projects and is also tasked with supporting transactions in the TMT market.

Legal 500 Data Privacy and Data Protection (2024)

GEISTWERT‘s partner-only practice provides ‘extremely fast and efficient advice’ at the intersection of data protection and IP, handling international data transfers, IT projects and data protection aspects of corporate transactions. The team, consisting of Constantin Kletzer, Juliane Messner, Max Mosing, Alexander Schnider and Rainer Schultes, also acts for clients facing hearings before the Austrian data protection authority and the courts, assisting with issues concerning user data disclosure requests and GDPR matters. The firm’s client base is comprised of companies ranging from digital media and pharmaceuticals to leisure and public bodies, whom it also advises on digital projects and initiatives including the launch of new customer programmes and services.


Excellent market knowledge of the sectors that are important to us, such as EdTech, IP law, pharmaceutical law, corporate law bundled in one law firm, solving problems in a client-oriented manner and providing extremely fast and efficient advice.’

‘Juliane Messner has the best knowledge of corporate law. So important for us because we are internationally established. Max Mosing provides us with solution-oriented support in the volatile environment of data protection law. Rainer Schultes is our trusted pharmaceutical law specialist.’

‘Juliane Messner and Max Mosing are hands-on, knowledgeable and understand the business of their clients. They are stand-out lawyers in the market and always give clients the feeling that their matters are in good hands.’

Chamber Global IP (2024)

GEISTWERT is a well-known law firm offering an excellent IP practice comprising patent and trade mark-related advice, including portfolio management and licensing. The law firm boasts particular prowess in contentious trade mark matters, excelling in infringement, opposition and cancellation proceedings. The team attracts clients from various industries, including gaming, automotive, food and drink and technology.


The team is highly specialised and has deep knowledge.“

„The lawyers offer quick responses, a solution-oriented approach and information in a language that is understandable for non-lawyers.“

The GEISTWERT team has a good understanding of complex issues and is strategically minded.“

„The lawyers are super quick, easy to understand and anticipate follow-up questions.“

„GEISTWERT provides a good assessment of the situation and is business-fluent and goal-oriented.“

Constantin Kletzer boasts a strong IP practice. He represents clients in trade mark disputes and further advises clients on non-contentious trade mark matters. He also assists with copyright issues, domain law and licence agreements. It is a pleasure working with Constantin Kletzer. He is very pragmatic and solution-oriented.“ „The response time is fast and at the same time he is competent, solution-oriented and aligned with the economic interest of the company. We are pleased to have Constantin Kletzer on board and do not want to do without him.“ „Constantin Kletzer shows prudence, pragmatism and a goal-oriented approach.“ „He is very smart, always available and commercially minded.“ „Constantin Kletzer has a very hands-on approach but can also work with the appropriate depth when necessary.“

Alexander Schnider boasts strong experience in IP mandates across the gaming, automotive and telecoms sectors. He advises clients on trade mark, licensing, patent and unfair competition mandates, as well as copyright issues. „He is easy, straightforward and his expertise is up to date.“ „Alexander Schnider is very efficient and competent, always paying attention to detail and looking at a matter from all possible perspectives.“ „He is a very good trade mark lawyer.“ „Alexander Schnider is super responsive, super fast and has good turnaround times. He helps us from a business perspective and has so much experience with bigger businesses that he can tell us what might not be a good deal.“ He guided us through the case very well, was always available for our worries and concerns and also summarised the judgments well in clear language.“

Max Mosing regularly handles a broad spectrum of IP mandates from licence agreements and rebranding to copyright and trade mark infringement and cancellation proceedings. He is particularly visible in the media, automotive and beverages sectors. Max Mosing is very open to innovation and provides very good strategies.“ „Max Mosing is very precise and very much to the point. In terms of advice, he is very reliable.“ „The cool composure with which Max Mosing handles complex matters and navigates difficult situations does not cease to astonish me.“ „He is very down to earth and provides good-quality work.“

Rainer Schultes regularly advises clients from the automotive, pharmaceutical and technology sectors on a variety of IP mandates, including trade mark, patent and unfair competition claims. He additionally assists with international domain disputes. „Rainer Schultes is a strong performer.“ „He is very strong in patent litigation and unfair competition cases.“

Italian and Austrian-qualified Juliane Messner is well placed to assist with IP mandates involving both jurisdictions. She advises prominent clients on trade mark questions, including complex infringement and opposition proceedings. Her practice also encompasses licensing agreements and portfolio management. „She can get into the nitty-gritty of all the different types of companies and she understands them well.“

Juliane Messner also is the only Austrian lawyer who was ranked as Foreign Expert for Intellectual Property in Italy (

WTR 1000 (2024)

“GEISTWERT’s service is always of excellent quality. All five partners not only have extremely deep knowledge of the specific fields they practice in but are also hands on and collaborative in a way that only benefits the client.” Alexander Schnider has a real entrepreneurial spirit and provides complete protection to gaming and media patrons. Alongside Rainer Schultes and Max Mosing, he has been advising Novomatic on all Austrian and EUIPO trademark matters. Schultes frequently emerges victorious from many skirmishes, while complex transactional instructions are bread and butter to Mosing. He works closely with Juliane Messner, and the duo receive warm plaudits from patrons: “Juliane and Max tailor their advice to the specific recommendations of our company and, due to their expertise, implement solutions that are highly customised and above all pragmatic. They always do an exceptional job and, on top of that, they are a pleasure to work with.” “When it comes to complex trademark litigation, Constantin Kletzer is the go-to attorney in Austria. He is a bright and deeply experienced lawyer with a keen sense for strategic solutions.”

ip stars

MIP IP Stars Firm Rankings 2023

As a firm, GEISTWERT received the following MIP IP Stars Firm Rankings 2023:

Patent disputes: Tier 1
Trade mark disputes: Tier 1
Copyright & related rights: Highly Recommended (only “highly recommended” and “recommended” available)
Trade mark prosecution: Tier 2

iam Patent 1000 (2023)

“Max has a superb knowledge of the law and how to apply it practically”, while “Juliane perfectly combines the world of IP law with transactions law – a unique talent, especially in international projects”.

iam Patent 1000 (2023)

Kletzer is a holistic counsellor and a fine choice for all intricate IP mandates. He also recently linked up with Mosing and Messner to aid Österreichische Post AG, a former Austrian monopolist and major state-owned company, with all aspects of its technology transfer, from strategic guidance to licensing and monetisation.

iam Patent 1000 (2023)

Schnider is extremely knowledgeable and can readily understand even the most intricate technical topics […]

iam Patent 1000 (2023)

The talent does not stop there though, with Alexander Schnider, Constantin Kletzer, Max Mosing and Juliane Messner all bringing their expertise to the mix. “It’s impressive how seamlessly the GEISTWERT partners work together. They truly act as a team and, most remarkably, they always select the best person for the job, ensuring their clients receive a personal and tailored service.” Of late, Schultes, Schnider and Kletzer represented TeleTan in an infringement claim against the bank Six Payment Systems for using TeleTan’s patented authentication system on their online payment authorisation platform.


iam Patent 1000 (2023)

First name on the roster Rainer Schultes also earns glowing feedback: “Rainer is an exceptional litigator when it comes to patent disputes. He is straightforward, intelligent and never short of a plan. His specific strength stems not only from his extraordinary grasp of patent law and relevant case law, but also from his comprehensive understanding of the pharmaceutical industry’s environment and overall business aims and strategy.”

iam Patent 1000 (2023)

“The IP community in Austria is a small but impressive one and GEISTWERT stands out among the top-tier firms. Its team of outstanding patent litigators across all technical domains are the go-to for strategic IP advice, patent litigation and transactional support. The overall experience of working with them is phenomenal.”

JUVE Patent Litigation 2023

This Viennese boutique has established itself as an authoritative IP outfit, particularly in litigation. It has long been a market leader in soft IP. In patent law, the practice led by Constantin Kletzer and Rainer Schultes has become the most persistent challenger to the market-leading firm Gassauer-Fleissner, thanks to its enormous presence in patent litigation. The fact that competitor Schwarz Schönherr, which had been weakened following a partner departure, was unable to keep pace with Geistwert was a further contributing factor. Like Gassauer-Fleissner, Geistwert is also one of the best-known Austrian patent litigation firms internationally. If Austrian issues arise at the UPC, both firms can depend upon being the first point of contact for litigation here, especially if IP teams without a local presence require cooperation partners.

Nevertheless, this is by no means a foregone conclusion and Geistwert would be wise to seek close cooperation with IP law firms in Europe. […] However, the team’s work in its most prominent case for Tele Tan against Mastercard concerning authentication procedures in online banking proves that the partners can handle international cases on the plaintiff side.

The firm’s trademark and unfair competition lawyers are often involved in cases for international clients, such as a German carmaker or a pharmaceutical company. Their best-known IP client with international reach is probably the Austrian beverage manufacturer Red Bull. The firm represents the company in IP litigation, as well as copyright, media and data protection law. IP advice goes hand in hand with IT and data protection advice due to the many international social media groups and streaming providers as clients.

The firm owes its success not only to its consistent focus on IP and IT law issues, but also to its partner-centric approach. The new challenges posed by the UPC will show whether this concept is sustainable in the long term or will slow down the dynamic development.


Consistent focus on IP issues with partner-centric approach; infringement litigation concerning pharma patents.

Recommended individuals

Constantin Kletzer (“excellent litigator who has seen it all”, competitor), Rainer Schultes (“well versed in patent litigation, especially pharma patents”, “the firm is a powerhouse in Austrian IP and Schultes is at the forefront”, competitors)

Legal 500 IP (2023)

‘Juliane Messner is the “commercial wonder woman” in the GEISTWERT team.‘

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