The Opportunity

EY Tax is a market leader, renowned for delivering sustainable growth and empowering our people to shape their own careers. Our diverse, collaborative team advises on high-profile transactions, combining technical expertise, innovation and a genuine focus on continuous development. Join us to work on challenging, multi-country projects in a supportive, dynamic environment where your impact truly matters.

We are seeking an experienced Senior Manager to join our London International Social Security (ISS) Centre of Excellence (COE) team. We’re looking for someone with strong technical expertise in EU legislation, bilateral social security agreements, and domestic social security/tax legislation, combined with change management skills to deliver high-impact communication and engagement strategies.

Client-facing experience in one or more of the following areas is essential:

• International Social Security (ISS)
• National Insurance Contributions (NIC)
• Assignment Management
• Expatriate Tax

The Team

EY’s ISS practice is the leading global provider of social security services. The London-based team includes ex-social security administration staff, qualified accountants, and tax advisors with backgrounds in expatriate tax, immigration, and assignment management. The team supports a wide range of global advisory and compliance work involving individuals relocating to and from the UK, as well as between other country combinations around the world.

What You’ll Do

• Lead the delivery of global ISS compliance services, including Certificates of Coverage, Modified National Insurance returns, and voluntary contributions.
• Provide expert technical advice on complex international social security issues, such as totalization agreements and multi-country assignments.
• Act as the primary point of contact for clients, building long-term relationships and ensuring high levels of satisfaction.
• Liaise with government authorities in the UK and abroad to resolve client matters.
• Contribute to the development and oversee the rollout of EY’s ISS strategy and service offerings across markets, people, and operations.

• Identify and pursue cross-selling opportunities within PAS and the broader EY service lines.
• Support the creation of thought leadership materials, including articles, presentations, and whitepapers on technical topics and broader trends such as technology.
• Mentor and coach junior team members, fostering both technical and professional growth.

• Coordinate efforts across EY’s global network and GDS back-office teams.
• Ensure operational excellence and financial discipline across engagements.

• Oversee risk management and ensure compliance with EY’s policies and regulatory standards.
• Monitor legislative changes and proactively advise clients on potential impacts.

About You
You’ll have:

• Extensive experience in international social security, ideally within a Big 4 firm or equivalent.
• Strong technical knowledge of UK and global social security systems.
• A proven track record of winning and managing complex projects and client relationships.
• Excellent communication, leadership, and organisational skills.
• The ability to work both independently and collaboratively in a fast-paced environment, with a strong commitment to personal growth and continuous learning.

What We Offer

• Global Exposure: Work with international clients and collaborate across EY’s global network.
• Career Progression: Lead high-impact projects and shape your professional journey.
• Support & Coaching: Learn from industry leaders and receive ongoing mentoring.
• Flexible Working: Hybrid model (minimum two days in the office) with a focus on work-life balance.
• Total Rewards: Competitive salary, comprehensive benefits, and exclusive EY perks.
• Inclusive Culture: A workplace where you belong, feel valued, and can thrive.

To help create the best possible experience during the recruitment process, please let us know if you require any disability-related adjustments or accommodations.

Ready to lead, inspire, and make an impact? Apply now.