The world's first real data on the global minimum tax lands the same week the United Kingdom writes the US side-by-side deal into law, and Canberra puts a number on the end of the bucket company.

The OECD's first empirical read finds Pillar Two raised EUR 79 to 109 billion in year one without deterring investment; the United Kingdom becomes the first major economy to legislate the side-by-side package; and Australia's trust minimum tax design puts corporate beneficiaries at an effective 42.9 per cent.

On 15 July 2026 the OECD published a working paper, 'MNE Responses to the Global Minimum Tax', the first empirical ex-post assessment of how multinational groups responded to the 15 per cent global minimum tax in its opening year of operation in 2024. The methodology matters to the credibility of the result. The paper uses group-level financial and ownership data and compares groups sitting just above and just below the EUR 750 million revenue threshold that determines whether the rules bite, isolating the effect of the regime rather than of the broader economic cycle.

The findings are consequential. Groups within scope recorded higher effective tax rates after the rules took effect, and the effect was stronger for those more exposed to top-up taxation, which is what a functioning minimum tax is supposed to do. The OECD found no evidence that the regime significantly reduced investment or employment at group level in year one, undercutting the central argument advanced against it. And on revenue, the paper estimates the minimum tax raised between EUR 79 billion and EUR 109 billion in its first year. That is lower than the most optimistic earlier forecasts but of the same order as the OECD's own ex-ante estimates; a separate, updated OECD economic impact assessment released the same week puts the annual revenue gain higher again, at roughly USD 91 billion to USD 155 billion, or 3.2 to 5.4 per cent of current corporate income tax receipts. The OECD cautions that the data is early and the numbers will move.

Why it matters. This is the first time the Pillar Two debate has been informed by outcomes instead of models, and the outcomes support the regime's continuation. A senior US Treasury official spent the same week at an international tax conference in Munich describing public country-by-country reporting as 'very dangerous' and defending the side-by-side agreement, and a separate OECD official signalled that a forthcoming economic assessment would trim revenue estimates on account of the substance-based income exclusion. The politics remain live. But a regime shown to raise revenue without deterring investment is one that finance ministries will defend, and the strategic planning assumption should now be permanence, not attrition.

What clients should do. Retire any residual internal narrative that treats Pillar Two as a temporary imposition to be waited out. Fold the durability finding into medium-term effective tax rate forecasting and into decisions on where to locate substance, given that the substance-based income exclusion is doing measurable work in the results. Where a group is close to the EUR 750 million threshold, note that the OECD's own method treats that boundary as the line where behaviour changes, and plan transactions and structure around it deliberately rather than incidentally.

On 13 July 2026, its Legislation Day, the United Kingdom published a substantial package of draft Finance Bill 2026-27 legislation and technical documents. The centrepiece for multinationals is a bill transposing the OECD's Pillar Two side-by-side package into the UK's Multinational Top-up Tax and Domestic Top-up Tax, in line with the OECD administrative guidance issued in January 2026, effective for accounting periods beginning on or after 1 January 2026, with further technical amendments applying mainly for periods beginning on or after 31 December 2026. The technical consultation closes on 7 September 2026. The package also carried draft rules on foreign permanent establishments, an oil and gas revenue levy, a securities transfer tax, the taxation of crypto asset loans and stablecoins, an international student levy and a wide field of personal and indirect tax measures.

Why it matters. The side-by-side package is the diplomatic settlement that accommodates the US minimum tax regime alongside the GloBE rules rather than colliding with it. Until now it has lived in OECD administrative guidance, which jurisdictions were expected to implement but had not yet enacted. The United Kingdom is the first major economy to convert it into draft domestic legislation, which sets a template others will follow and gives in-scope groups the first concrete statutory text on how the US carve-out will actually operate in a GloBE jurisdiction. It also confirms, in the most tangible way available, that the Pillar Two framework is being built out rather than wound back.

What clients should do. For any group with a UK constituent entity or UK top-up tax exposure, read the draft side-by-side provisions against your current GloBE modelling and identify where the US accommodation changes a top-up outcome you had assumed. Diarise the 7 September consultation and consider a submission where the drafting is ambiguous on your fact pattern, because first-mover legislation tends to harden into the reference text. Treat the 1 January 2026 effective date as live for period-end provisioning now, not as a 2027 problem.

The Treasury's consultation paper on the 30 per cent minimum tax on discretionary trust distributions, released on 8 July with submissions closing 31 July 2026, has now been unpacked in detail, and the design is more consequential than budget night implied. From 1 July 2028, a trustee will pay 30 per cent tax on the trust's taxable income, with individual and other non-corporate beneficiaries receiving a non-refundable minimum tax offset. Corporate beneficiaries, however, get no offset. A company beneficiary that pays 30 per cent corporate tax on its share of trust income pays that on top of the 30 per cent already paid by the trustee, with no credit, producing an effective rate of 42.9 per cent on the amount it actually receives. On $100,000 of trust income routed to a bucket company, that is $60,000 of tax. The paper treats this as an intentional design feature, and practitioners reading it have concluded it ends the bucket company strategy for groups that keep discretionary trusts past commencement.

Three further design points deserve attention. The paper offers broad capital gains tax rollover relief, modelled on the small business restructure rollover but wider, available for three years from 1 July 2027 to move assets out of a discretionary trust into a company or fixed trust without immediate tax; but that relief intersects unresolved with state transfer duty and with trust law, since transferring a broad beneficiary class's assets into a company with restricted shareholders can breach a trustee's fiduciary duty and invite beneficiary litigation. Distributions to foreign resident beneficiaries, to the extent they comprise dividends, interest and royalties subject to foreign resident withholding tax, are carved out, preserving treaty and withholding outcomes for cross-border structures. And the treatment of a trust's excess franking credits, refund or carry-forward, remains open, as does the threshold question of what separates a 'fixed' trust from a 'discretionary' one for the measure's purposes.

Why it matters. This is the Budget answering back on the distribution side at the moment the deemed-dividend side has been read back. Bendel removed the foundation for treating an unpaid present entitlement to a corporate beneficiary as a Division 7A loan; the trust minimum tax reaches much of the same ground through a charge on distributions, and the consultation expressly asks how the two should interact, while noting the 2018-19 announced-but-unenacted measure on unpaid present entitlements is unlikely to remain unenacted much longer. A group reading the Bendel win without reading this consultation is reading half the file.

What clients should do. Treat the fortnight to 31 July as a genuine window. Model the 42.9 per cent corporate-beneficiary outcome against every bucket-company arrangement in the ownership chain, and against the residual section 100A and Part IVA exposure, rather than assuming Bendel has cleared the field. Where a restructure out of a discretionary trust is contemplated, price the state transfer duty and trust-law exposure alongside the CGT rollover, because the rollover's appeal falls away if duty or a fiduciary-duty dispute follows. Consider a submission, particularly on the corporate-beneficiary double tax, the franking-credit treatment and the fixed-trust definition, and document any decision taken now as a deliberate response to a known future measure.

The week's other Pillar Two developments were less about deadlines than about the plumbing that makes a single central filing release a group from filing everywhere else. Türkiye published Presidential Decision No. 11511 on 11 July, setting out, in three annexes, the jurisdictions qualifying for the QDMTT safe harbour, those applying a qualified domestic minimum tax and those applying the income inclusion rule, each covering more than 40 jurisdictions and effective retroactively for accounting periods beginning on or after 1 January 2024. Germany's Federal Council approved the amended regulation implementing its minimum taxation law; and the ATO's update to PCG 2025/4 folded the OECD common understanding on central filing and exchange into Australia's transitional penalty approach for the 2024 year.

Why it matters. Central filing only relieves local filing where the specific exchange relationship exists and the host jurisdiction's regime is confirmed as qualified, and this is the season those confirmations are being enacted country by country. A safe-harbour annex published, a domestic regime updated to the latest commentary, an exchange understanding folded into a compliance guideline: each changes the practical answer to the question every in-scope group is asking, which is whether it can file once and be released everywhere else, or not yet. The Türkiye lists are also a reminder that a jurisdiction's 'qualified' status is not static; it rests on keeping pace with the moving OECD text, so a group cannot verify the safe-harbour position once and file it away.

What clients should do. For each jurisdiction a group touches, record whether the local regime and the exchange relationship are actually operational, not merely legislated, and treat 'central filing releases local filing' as a proposition to be verified per country rather than assumed. Where a domestic regime has recently updated to the latest OECD commentary, refresh the qualified-status assumption in the model, because safe-harbour and top-up outcomes depend on it. Use the Türkiye annexes to confirm the safe-harbour position for any Turkish member of the group.

Several jurisdictions moved on the mechanics of transfer pricing in the same week, and the pattern is a migration of the compliance burden from the annual return into the design of documentation and disclosure. Vietnam issued a new decree on related-party transactions, effective from 1 July 2026 and applying from the 2026 corporate income tax period, that raises the documentation exemption revenue threshold from VND 200 billion to VND 500 billion, aligns the country-by-country reporting threshold to EUR 750 million, sets a priority order for comparable data sources led by public information, and refines when a borrowing or lending arrangement counts as related-party. Colombia's Supreme Administrative Court held, in a decision of 2 July, that a domestic Colombian interest rate cannot be applied to a foreign-currency loan to a foreign related party because the markets are not comparable, and confirmed that passive association, the implicit support a group member enjoys, does not itself require separate remuneration under paragraph 7.13 of the OECD Guidelines. A Canadian Federal Court remitted an APA-related interest-relief decision in the LG Electronics matter for redetermination, and the United Arab Emirates clarified the treatment of downward transfer pricing adjustments in the corporate tax return.

Why it matters. None of these is a change to a tax rate; each changes the terms on which exposure is measured, documented and disclosed. Vietnam's higher thresholds narrow the documentation net for smaller flows while retaining full country-by-country obligations; Colombia's reasoning is a useful authority for pricing foreign-currency intercompany debt and for resisting a blunt domestic-rate substitution; and the UAE's guidance on downward adjustments matters for any group truing up Emirati results to arm's length. For a group operating across these jurisdictions, the work is moving upstream, into getting the documentation, the comparables and the disclosures right before the return is filed.

What clients should do. For Vietnamese dealings, re-test documentation and country-by-country obligations against the new decree now, since it applies from the current 2026 period. Where intercompany debt is denominated in a foreign currency, hold the Colombian reasoning in support of a currency-matched benchmarking approach and against a domestic-rate challenge. For UAE members, confirm the mechanism and evidence for any downward adjustment before lodgment. Across the group, treat documentation design, not the return, as the point at which transfer pricing exposure is now won or lost.

PCG 2025/4 updated for central filing. On 9 July the ATO amended Practical Compliance Guideline PCG 2025/4 to reflect the OECD common understanding on central filing and exchange of the GloBE Information Return for the 2024 fiscal year. Where the GIR has been centrally filed in a listed jurisdiction by the relevant deadline and the local notification lodged, the 2024 implementing jurisdictions will waive local GIR penalties and not enforce local filing before the relevant exchange deadline.

Australia and Japan agree the arbitration mode. The ATO and Japan's National Tax Agency have settled the mode of application of the mandatory binding arbitration process under Part VI of the OECD Multilateral Instrument as it modifies the Australia-Japan double tax agreement, including three-member panels chaired by a non-national and detailed rules on requests, terms of reference and arbitrator independence. The memorandum gives taxpayers a clearer route to resolution where a mutual agreement procedure stalls.

Director penalties: Ostwald v FC of T. In Ostwald & Ors v FC of T [2026] FCA 868 (3 July), the Federal Court dismissed three directors' judicial review applications against superannuation guarantee charge director penalties, holding that a partial discharge of one director's penalty from an income tax credit was not 'recovery' within section 269-35(4A)(a)(ii) of Schedule 1 to the Taxation Administration Act 1953, so that no reviewable decision arose for two of the brothers, and that the Commissioner could disregard information supplied outside the 60-day window.

A working view of the milestones now in play, updated for UK Legislation Day, the OECD first-year assessment, the Turkiye annexes and the Australian trust consultation. The statutory GloBE Information Return date has not moved; jurisdictions are varying only the enforcement posture and the domestic implementation timetable. Confirm each entity's obligation against its local rules and verify exchange activation before relying on central filing.