International Tax & the Multilateral Instrument (MLI) - A Practical Guide for UK Advisors

Introduction

This webinar provides a practical, post-MLI perspective for advisers working with UK-facing structures. Rather than reiterating OECD texts, it focuses on the real-world application of MLI-modified provisions, including the Principal Purpose Test (PPT), tie-breaker rules, permanent establishment (PE) expansions and dispute resolution mechanisms, in audits, clearances and treaty claims.

You will learn how to identify legacy structures that may now be vulnerable under the MLI, how to frame robust business-purpose narratives and what an ‘MLI-ready’ evidence pack looks like for practical client scenarios.

While primarily aimed at UK advisers with international clients, this webinar is also suitable for practitioners across other MLI-participating jurisdictions.

What You Will Learn

This webinar will cover the following:

• MLI architecture in practice
• Brief overview of how the MLI modifies covered tax agreements relevant to UK taxpayers
• Understanding reservations and notifications: why not all treaties are affected in the same way
• How to quickly check whether a specific treaty relationship is MLI-modified and where
• Principal Purpose Test (PPT) - operational impact
• How PPT interacts with traditional treaty interpretation principles
• Key indicators of an unacceptable ‘principal purpose’ vs defensible commercial structuring
• Building contemporaneous evidence: decision logs, board minutes, functional analyses, financing files
• Illustrative case patterns: holding, financing and IP structures post-MLI - what now passes, what is challenged
• Residence tie-breakers and dual residence post-MLI
• Shift from mechanical tie-breakers to mutual agreement procedures (MAP) for companies
• Practical consequences for groups with ‘central management and control’ touchpoints in the UK
• How to reduce the risk of unresolved dual residence and deal with it in documentation, policies and governance
• PE expansion and dependent-agent rules under the MLI
• How the broadened DAPE concept and anti-fragmentation provisions apply to commissionaire, marketing, procurement and remote-working models
• Typical risk scenarios for UK-headquartered or UK-market groups (fragmented warehousing, regional hubs, roaming decision-makers)
• Practical mitigations: authority matrices, contracting policies, internal guidance and monitoring
• Treaty anti-abuse: PPT vs LOB vs domestic GAAR
• Coordinating MLI-modified treaties with UK GAAR, targeted anti-avoidance rules and anti-hybrid rules
• Managing overlaps: how to approach a structure review where multiple anti-abuse tools could apply
• Drafting streamlined internal ‘gatekeeper’ checklists for advisers
• MAP and dispute prevention in an MLI world
• When to consider MAP where PPT/PE positions are disputed
• How to make your files ‘MAP-ready’: clarity of fact pattern, timeline and alternative positions
• Role of APAs, clearances and advance engagement with tax authorities
• Case studies and practical toolkit
• Short case studies: a holding/financing chain; an IP/licensing model; and a regional sales structure tested against MLI-modified rules
• Takeaway templates: a PPT assessment note, an MLI treaty-impact checklist, a PE/fragmentation risk matrix

This pre-recorded webinar will be available to view from Monday 21st September 2026

Alternatively, you can gain access to this webinar and 2,101 others via the MBL Webinar Subscription. Please email webinarsubscription@mblseminars.com for more details.