Arnold & Siedsma

WTR Research

The WTR 1000 focuses exclusively on trademark practice and has firmly established itself as the definitive 'go-to' resource for those seeking world-class legal trademark expertise.

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Celebrating its centennial in 2020, “Arnold & Siedsma maintains and defends trademarks around the world quickly and efficiently” through 11 outposts across Europe and a vast international network. Its “supportive, strategic and detail-oriented practitioners go the extra mile as a matter of course and put their clients’ interests first at all times”. Group co-captains Karin Becks and Joop Elzas oversee the global portfolios of Mustad Hoofcare and accountancy group BDO respectively. “Karin is consistently thorough, prompt and has an excellent understanding of the industries she operates in. She always looks to achieve the maximum protection available when filing applications and asks thoughtful questions which open extra pathways to a great solution. Karin is a person of great integrity and warmth, and has a way of making everyone feel included.” Elzas likewise receives glowing feedback: “He is a great linking pin to any operation, as his experience and sound and concise advice allow decision makers to move quickly. He is a great strategic thinker with fantastic connections too.” Oppositions ace Sandra Bauwens “gives pragmatic, cost-effective guidance with a view to providing strategic and realistic input that adds to the overall picture. She does not sit on the fence and her advice is commercially relevant and timely”.

Firm Profile

Arnold & Siedsma was established in 1920 and over the past 100 years has become a full-service IP firm, offering prosecution and litigation services in relation to patents, trademarks and designs. Our team consists of more than 60 technical and legal professionals. We operate from the Netherlands, Belgium, Germany and Switzerland

As part of a full-service IP firm, our trademark team explores the best suitable strategy for our clients with a broader view than just trademarks. We benefit from IP awareness that is created in the field of patents as well as litigation, and vice versa. But the broader view also reveals solutions to complex issues that are out of the box. We also dare to say “no” to our clients. We have one goal: to meet our clients’ interest in the best possible way.

This can be achieved only by curious people who embrace new challenges and want to experience what is happening in this new world. People involved with clients’ business, seeing the broader picture and advising how IP suits best and brings most. This approach is the pride of our firm!

ISO 9001 certified

For the past 100 years, we have been a reliable partner to our clients with regard to all IP issues. In 2015 we became the first large Dutch IP agency with foreign offices to be ISO 9001 certified. This certification is valid for all our offices in all countries. We are proud of our ISO 9001 certification because it confirms the high quality of the processes of our operation.


At Arnold & Siedsma we believe in customised work and this can be seen in the way we operate: say what you do, do what you say, prove it.

The lines of communication with our specialists are short and personal. Service is our top priority. We stay in close touch with our clients so that we can provide them with a fast and responsive service. At Arnold & Siedsma we follow the four eyes principle, and we will assign a dedicated team to each of your cases. The long-term relationships we foster ensure that we know our clients’ business and strategy, which in turn means that the team will be able to give you the best advice for your business, in line with your multi-annual planning. Our attorneys will maintain regular contact with you. The protection of an innovation is of great economic value, but can also be costly. This is why, at Arnold & Siedsma, we attach great importance to clear communication throughout the entire process and we try to work as cost effectively as possible.

Because we are a full-service IP provider, we handle all IP work. Our patent attorneys, trademark attorneys and design attorneys work closely with our litigation team. We can pull together a team from several disciplines, enabling us to handle cross-discipline IP cases quickly, seamlessly and without unnecessary costs. Arnold & Siedsma is uniquely positioned as a service provider in the Netherlands thanks to this team-based approach.

Arnold & Siedsma is your actively involved and knowledgeable partner. We are happy to be of service and contribute to our clients’ ideas.

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