The Expat Tax Manager is responsible for overseeing all tax matters related to both UK‑based and internationally mobile colleagues, including assignees, commuters, short‑term business travellers, International Remote Workers, and permanent transfers. This role ensures full compliance with global tax regulations, leads the delivery of annual tax compliance processes, mitigates organisational risk, and provides expert guidance on cross‑border tax issues. As the organisation’s subject matter expert in expatriate taxation, the Expat Tax Manager will work closely with the People Team, Payroll, Finance, and external tax advisors to deliver a seamless, efficient, and compliant colleague experience. Lead all global mobility tax compliance activities, including tax returns, social security, shadow payroll, and annual reporting. Manage UK and international tax obligations for assignees, business travellers, remote workers, commuters, and permanent transfers. Provide expert advice on cross‑border and multi‑jurisdictional tax matters, including treaty considerations and country‑day thresholds. Review tax legislation and external advisor recommendations to ensure ongoing global compliance. Support colleagues before, during, and after international assignments and relocations. Partner with People, Payroll, Finance, and Global Mobility to ensure accurate tax reporting, payments, and reconciliations. Review and support tax elements of assignment planning, cost projections, and remote‑working arrangements. Ensure timely settlement of tax authority payments and tax‑equalisation balances. Manage relationships with external tax providers and review all vendor outputs for quality and accuracy. Communicate complex tax concepts clearly to stakeholders and build strong cross‑functional relationships.