Practical UK Pillar 2 compliance, without the full-service overhead
UNW helps UK and overseas-headquartered multinational groups meet their UK international tax reporting obligations through specialist, proportionate support.
We can manage the full compliance process or work with calculations prepared by your in-house tax team, overseas parent or another adviser, taking responsibility for completing and submitting the relevant UK filings.
Our services cover UK Pillar 2 self-assessment returns, including Domestic Top-up Tax and Multinational Top-up Tax where relevant, Overseas Return Notifications (ORN), UK-filed GloBE Information Returns (GIR), Country-by-Country Reporting (CbCR), testing and assurance.
International tax compliance in a changing world
International tax reporting is no longer a series of isolated returns. Multinational groups must coordinate entity data, accounting information, tax attributes, ownership records and governance across multiple regimes. OECD transparency initiatives, domestic implementation and digital filing standards are increasing both the volume of data and the need for consistency.
Pillar 2 adds a jurisdictional effective tax rate framework and top-up tax reporting for large groups. In the UK, Multinational Top-up Tax and Domestic Top-up Tax apply for accounting periods beginning on or after 31 December 2023, subject to the detailed statutory rules for the relevant period.
For a qualifying group, the UK compliance package will generally involve the UK Pillar 2 self-assessment return together with either a GIR filed directly with HMRC or an ORN where the GIR has been filed with an overseas qualifying authority and the relevant information will be exchanged with HMRC. An ORN does not replace the UK self-assessment return.
The GIR is the standardised information return for the GloBE rules, bringing together group, entity, ownership, election, safe-harbour and jurisdictional calculation information. CbCR remains a separate regime but may support Pillar 2 scoping and the Transitional CbCR Safe Harbour, subject to the relevant conditions and reconciliation of the underlying data.
Our UK Pillar 2 compliance services
Our services can be tailored around your existing team, systems and advisers. We agree responsibilities, information requirements, review procedures and filing requirements at the outset, allowing you to choose the level of support that best fits your existing capabilities.
| Service | How UNW can help |
|---|---|
| End-to-end Pillar 2 compliance | We can manage the full UK compliance process, including scope assessment, registration support, calculations, review, UK returns, GIR or ORN requirements, submission, payment support and ongoing governance. |
| UK Pillar 2 self-assessment return | We can prepare and submit the UK Pillar 2 self-assessment return, including the relevant Domestic Top-up Tax and Multinational Top-up Tax information. We can prepare the underlying calculations or work from calculations approved by your team. |
| Overseas Return Notification | Where the GIR is filed with an overseas qualifying authority, we can confirm the UK filing route, prepare and submit the ORN and coordinate it with the separate UK Pillar 2 self-assessment return. |
| GloBE Information Return | We can manage the GIR process from data gathering and calculation through to validation and submission, or prepare and file the GIR using calculations and information provided by your team. |
| Country-by-Country Reporting | We can prepare the CbCR analysis and report from source information or validate and submit a report prepared using your group’s existing data and processes. |
| Testing and assurance | Where calculations have been prepared internally or by another adviser, we can perform agreed review, sense-checking and assurance procedures before submission. |
| Managed annual compliance | We can manage the recurring compliance cycle covering calculations, returns, notifications, submissions, deadlines and governance, with a clear annual timetable and agreed responsibilities. |
Why choose UNW
Our approach is built around what in-house tax teams actually need: practical UK filing support, a clear division of responsibilities and direct access to experienced specialists.
| UK filing expertise | Practical experience across the UK Pillar 2 self-assessment return, direct GIR filings and ORNs. |
| Flexible delivery | End-to-end compliance or filing support based on calculations prepared by your team or another adviser. |
| Practical approach | Clear information requests, responsibilities, review points and filing plans. |
| Proportionate scope | Testing and assurance can be added only where additional comfort is required. |
| Predictable pricing | Software and professional fees are kept distinct and agreed in advance. |
| Direct specialist access | Work directly with experienced corporate and international tax advisers. |
A flexible service built around your team
- End-to-end UK Pillar 2 compliance: UNW manages the process from calculations and data gathering through to preparation, validation and submission of the UK Pillar 2 self-assessment return and UK-filed GIR.
- UK self-assessment return and ORN support: the GIR is prepared and filed centrally overseas, while UNW prepares and submits the UK Pillar 2 self-assessment return and Overseas Return Notification.
- Client-led calculations with UNW filing support: the group retains responsibility for its Pillar 2 calculations, while UNW provides the agreed review and validation before preparing and submitting relevant UK filings.
Our compliance process
| 1. Tax calculations | 2. Data sharing | 3. Review and assurance | 4. UK filing and submission |
|---|---|---|---|
| Pillar 2 calculations are prepared by UNW or provided by the group, its shared service centre or another adviser, depending on the agreed scope. | The relevant entity, ownership, accounting and tax information is gathered through a controlled data request. | UNW prepares or reviews the calculations and performs the agreed level of testing, sense-checking and assurance. | UNW prepares, validates and submits the UK Pillar 2 self-assessment return and, as applicable, the GIR or ORN. |
At each stage, responsibilities are documented. Issues are tracked to resolution, changes are version-controlled and the final filing pack records what was submitted, when it was submitted and the supporting evidence retained.
Flexible support for UK and overseas-headquartered groups
Whether Pillar 2 is managed centrally or UK compliance sits with a local tax or finance team, we tailor our role around your existing resources, systems and processes.
Talk to us about your UK Pillar 2 obligations
Discuss your calculation, review and filing requirements with a member of our specialist team.