SIX drives the transformation of financial markets.



What sets us apart drives us ahead: between local roots and global relevance, we are a unique blend of tradition and future, of foundation and growth. We value bright minds and inspire them to grow with their ideas. Come and shape the future of finance with us.




Senior Tax Expert



Warsaw, Madrid | Working from home up to 40% | Reference 7955



Are you interested in working in a highly dynamic environment with international tax exposure? We are looking for an experienced Senior Tax Specialist to join our Group Tax / Tax Management team in Spain. This role requires a self-driven professional who independently manages key tax matters, including tax compliance, tax planning, and advisory support to the group on topics such as restructurings and acquisitions. A particular focus lies on FATCA and QI compliance, where deep expertise and practical experience are essential. Beyond this, you will cover a wide spectrum of responsibilities within an international tax function.




What You Will Do

• Own and manage FATCA and QI compliance processes, including reporting, controls, and coordination with key stakeholders such as the tax operations teams in Switzerland


• Oversee EU DAC obligations, ensuring accurate data validation, documentation, and regulatory submissions


• Act as a tax business partner to BSS Business Units, providing advisory support on products, services, and operational tax matters


• Collaborate closely with Swiss and Spanish teams to align processes and ensure consistent tax governance standards


• Support transfer pricing topics, including data preparation, documentation, and coordination with internal experts


• Take responsibility for corporate tax compliance Spain or Switzerland and tax reporting across relevant entities


• Contribute to tax planning initiatives and provide support on group-wide projects, including restructurings and M&A activities


• Provide comprehensive tax advice on a broad range of international and local tax matters within the group

What You Bring

• Degree in Tax, Business, or Economics


• A profound knowledge base of the legal and compliance framework, the relevant guidelines and best practice in the area of FATCA and QI


• Solid experience in international or regulated environments with exposure to EU or US tax reporting obligations


• Ability to work independently with structured and reliable approach in compliance-driven environments


• Strong communication skills to collaborate across teams and explain complex tax matters to internal and external stakeholders clearly


• Needed Language Skills: English and Spanish

If you have any questions,
check out our FAQ page or call Yuliya Stoyko at +34 917095993.



For this vacancy we only accept direct applications.



Diversity is important to us. Therefore, we are looking to receiving applications regardless of any personal background.




What We Offer




Flexible Work Models

We trust our employees and offer a work environment that is well-balanced, productive and fosters success.




Personal Development

You will benefit from a culture of continuous learning and feedback. Your personal growth is supported through an extensive learning offering.




Agile Working Methods Whether through scrum or design thinking,

we solve exciting tasks together in teams.