Advokatfirmaet Thommessen AS advises on large IT and digital transformation projects and frequently assists with GDPR and other emerging data regulatory matters, including AI. The firm also has a cybersecurity and cyber assurance practice and handles large-scale technology disputes. The practice is led by Espen Werring, who advises private sector clients on the development, transformation, maintenance, and operation of IT processes, with Christopher Sparre-Enger Clausen providing expertise in data protection and cybersecurity.

Legal 500 Editorial commentary

Accolades

Client satisfaction: Sector knowledge

Client satisfaction: NPS ®

Testimonials

Collated independently by Legal 500 research team.

‘I work with lawyers in multiple countries and companies. On TMT, Thommessen are my favourites. For mainly these reasons: They are knowledgeable about me as a client, and understand how my industry needs a different "dialect". Over the years, I've also found that they have an uncanny ability to remember what we have done in the past, even if we are a mid-sized account. Thommessen also manages to adapt their style and tone to the needs of the moment, while at the same time giving great counsel and expressing disagreement with respect.’
‘Our partner Christopher Claussen is our main contact. He's knowledgeable, smart, and solution-oriented. He knows when to use the law, and when to use common sense.’
‘Espen Werring is by far the best lawyer we have used in the area of ICT-sourcing and negotiations. We are also very pleased with Christopher Sparre Enger Clausen and his deep knowledge regarding legal aspects relating to cybersecurity.’
‘Working with the Thommessen team has been a standout experience. What impressed us most was their ability to combine deep legal expertise with a practical, business-minded approach. They do not just advise, they partner with you, taking the time to understand your goals and tailoring their advice accordingly.'
‘We have worked with many firms over the years, but the Thommessen team is something else, and I mean that in the best possible way. They’re not just brilliant lawyers (which they are), they are also the kind of people you would actually want to be stuck in an airport with during a flight delay.'

Key clients

Microsoft Corporation
Samsung Electronics AB
Sparebank1 Gruppen
AutoStore AS
Nordea
Remarkable AS
Bomega AS
Kahoot! AS
Eika Gruppen
Lyse Tele
Bolt
Kahoot!

Work highlights

Serves as Microsoft's preferred legal service provider in Norway, supporting a wide range of business needs both domestically and internationally. Thommessen advises on data protection, cybersecurity, dispute resolution, regulatory compliance, public procurement, contract drafting, and other legal matters.

Advised Rema 1000 Norge AS, one of Norway’s largest grocery retailers, on the strategic procurement and rollout of a new POS system across its stores in Norway and the wider Nordic and Baltic regions.

Provides ongoing legal counsel to Kongsberg Gruppen ASA and its subsidiaries on regulatory, contractual, and cybersecurity issues within the maritime and military technology sectors.