Global Mobility Tax Solutions Expert

Posted:
12/21/2025, 4:00:00 PM

Location(s):
Warsaw, Masovian Voivodeship, Poland ⋅ Masovian Voivodeship, Poland

Experience Level(s):
Junior ⋅ Mid Level

Field(s):
Accounting

Workplace Type:
Hybrid

Company:

Mercer

Description:

We are seeking a talented individual to join our Global Mobility Tax Research team at Mercer Services. This role will be based in Warsaw – al. Jerozolimskie 98, Nimbus office. This is a hybrid role that has a requirement of working at least three days a week in the office.

The Global Mobility Tax Solutions Expert will focus on developing innovative Personal Income Tax (PIT) solutions globally, enhancing existing tools such as Excel PIT calculators and cost projection registers, and delivering valuable tax data to international companies sending employees abroad.

We will count on you to:

  • Translate clients’ needs into Tax and Economic Research Team products
  • Deliver new tax products and develop existing ones in cooperation with the Global Mobility Product Owner
  • Provide tax and cost projection solutions for clients across various tax jurisdictions
  • Improve existing tools such as Excel models and calculators to produce reports and data sets
  • Develop and translate complex tax concepts into calculators and/or calculations
  • Support implementation process of new tax laws
  • Apply knowledge of international payroll management and global residual tax calculation
  • Manage and coordinate vendors related to income tax, equity compensation, payroll, immigration, relocation, business travelers, and social security
  • Collaborate with junior colleagues to deliver multiple products annually
  • Ensure a high level of service and client satisfaction
  • Identify improvement opportunities and drive process changes within the team and Mobility teams

What you need to have:

  • Minimum 3 years of experience in Personal Income Tax, Global Mobility processes, international taxation advisory, payroll, or accounting in an international organization
  • MA or BA degree in Economics, Law, or related field
  • Strong knowledge of Personal Income Taxation systems in different countries
  • Project management experience focused on implementing or developing tax tools/tax calculators for clients
  • Relevant tax, payroll, accounting, or related professional qualification
  • Very strong analytical and problem-solving skills
  • Ability to work effectively with colleagues and stakeholders at various organizational levels
  • Fluent written and spoken English
  • Proficiency in MS Office (Excel, Word) and strong general computer literacy

What makes you stand out:

  • Knowledge of technology and tools for international assignments, global payroll, and employment tax calculations
  • Experience in PIT global tax advisory services, including preparing legal advice for clients

Why join our team:

  • We help you be your best through professional development opportunities, interesting work and supportive leaders.
  • We foster a vibrant and inclusive culture where you can work with talented colleagues to create new solutions and have impact for colleagues, clients and communities.
  • Our scale enables us to provide a range of career opportunities, as well as benefits and rewards to enhance your well-being.

If you would like to apply for this position, please send your CV in English.

Mercer, a business of Marsh McLennan (NYSE: MMC), is a global leader in helping clients realize their investment objectives, shape the future of work and enhance health and retirement outcomes for their people. Marsh McLennan is a global leader in risk, strategy and people, advising clients in 130 countries across four businesses: Marsh, Guy Carpenter, Mercer and Oliver Wyman. With annual revenue of $24 billion and more than 90,000 colleagues, Marsh McLennan helps build the confidence to thrive through the power of perspective. For more information, visit mercer.com, or follow on LinkedIn and X.

Marsh McLennan is committed to creating a diverse, inclusive and flexible work environment. We aim to attract and retain the best people and embrace diversity of age, background, disability, ethnic origin, family duties, gender orientation or expression, marital status, nationality, parental status, personal or social status, political affiliation, race, religion and beliefs, sex/gender, sexual orientation or expression, skin color, or any other characteristic protected by applicable law.

Marsh McLennan is committed to hybrid work, which includes the flexibility of working remotely and the collaboration, connections and professional development benefits of working together in the office. All Marsh McLennan colleagues are expected to be in their local office or working onsite with clients at least three days per week. Office-based teams will identify at least one “anchor day” per week on which their full team will be together in person.