CMS is recruiting a Global Mobility Tax Assistant Manager, you can be based in either our Edinburgh, Glasgow, Aberdeen, Sheffield or Leeds office. To support the Senior Global Mobility Tax Manager in delivering pragmatic, compliant and commercially focused global mobility tax support across the firm. The role focuses on advising the business on UK and international tax, social security and permanent establishment risks arising from internationally mobile partners and employees, and on supporting the operation and continuous improvement of the firm’s global mobility frameworks and processes. This is an in‑house, advisory and operational role within a professional services / law firm environment, working closely with HR, finance, legal and external advisers. Key Responsibilities Support the provision of UK and international tax input on international secondments, cross‑border working, international remote work and business travel scenarios. Assist in assessing UK PAYE, NIC and overseas payroll and other obligations for inbound and outbound individuals. Support analysis of double tax treaty positions, short‑term business visitor rules and social security coverage (including A1/CoC considerations). Help identify and manage permanent establishment and corporate tax risks arising from international working arrangements. Support the Senior Manager in reviewing mobility requests against firm policy and documenting tax risk positions and assumptions. Coordinate with external tax advisers where formal advice is required and help review advice received for consistency with firm approach. Support UK and overseas compliance obligations, including monthly shadow payroll, Appendix 4, and Appendix 8 reporting. Assist in managing data, tracking and reporting related to internationally mobile populations. Help maintain audit trails and internal documentation. Provide clear, practical guidance to HR, partners, line managers and other stakeholders on global mobility tax matters. Support process improvements, standardisation and the development of guidance notes, templates and training materials. Skill set - Essential Solid UK Global Mobility / employment tax knowledge, including: PAYE and NIC implications for internationally mobile individuals Short‑term business visitors and treaty‑based relief principles Understanding of international mobility tax concepts: Inbound and outbound assignments International remote working / cross‑border working requests Shadow payroll and host country tax exposure (conceptual, not necessarily hands‑on processing) Working knowledge of social security coordination (UK NIC, A1/Certificates of Coverage) Desirable Exposure to permanent establishment risk indicators in professional services environments LI-DH1 What’s in it for you? We want to reward you today and help you plan for tomorrow. We appreciate that everyone is different, therefore we have designed a benefits system that offers choice and flexibility based on individual needs and lifestyles. To name a few, these include: Competitive basic salary (reviewed annually) Flexible, hybrid working policy Generous bonus scheme Up to 25 days holiday (rising to 28 days with service) Holiday exchange scheme Private medical insurance Enhanced parental leave Reasonable adjustments and accommodation for disabled talent in accordance with the Equality Act 2010. If you would like to read more information regarding our range of benefits, please visit our Rewards & Benefits page on our website. Please note that we have a preferred agency panel in place. Only applications submitted via the portal at the point of instruction will be accepted.