Tristan is Head of Dentons' Technology, Media and Telecoms (TMT) practice for the UK, Ireland and Middle East. He leads one of the most highly ranked and largest specialist TMT practices with more than 90 dedicated partners, fee earners and professionals.

Tristan advises on high-value technology and commercial projects, typically in regulated sectors. He has been recognized as a "Leading Partner" in FinTech and "Next Generation Partner" in IT & Telecoms by Legal 500 2025, and also serves as Co-Chair of Dentons' Global FinTech Group.

Tristan's expertise includes advising on:

• Commercial contracts – including outsourcing, distribution agreements, collaboration agreements, introducer agreements and contracts for the supply of goods and services.
• Technology contracts – including e-Commerce, application development, application management, hosting, re-platforming and migration to cloud services, software licensing, Software as a Service (SaaS) and AI procurement.
• FinTech and payments – including merchant acquiring, payment gateway and other payment service agreements, introducer and distribution agreements for financial products and digital banking.
• Telecoms and space – including communication services agreements, MVNOs, the rollout of fiber optic networks, capacity agreements and roaming agreements, and telecoms and space laws, including advising governments and regulators globally on major regulatory projects.

Clients comment in Legal 500: "Tristan Jonckheer is a trusted advisor, valued by key stakeholders. He provides commercial legal advice in a clear and articulate manner, often going above and beyond, making him stand out from his competitors" and "Tristan Jonckheer and his team work tirelessly to quickly understand and get to the heart of the issue, working with an open dialogue to find a suitable solution. This shows their experience and expertise in complex transactions".