The tax rules that only start once you are big
Above certain sizes, a group takes on a separate layer of tax compliance: a global minimum tax, country-by-country data, transfer pricing files and a new schedule of cross-border transactions, a named Senior Accounting Officer, a published tax strategy and notifications of uncertain positions. Each one carries its own deadline and its own penalty regime.
TaxDigit plans, prepares and files this work for UK groups and for the UK companies and branches of overseas groups. We bring international tax and transfer pricing experience to every engagement, and we coordinate with your group tax team, your overseas advisers and your auditor so the numbers agree everywhere they appear.
- Large UK groupsFamily-owned, founder-led and investor-backed groups above the large company thresholds.
- Inbound multinationalsUK subsidiaries and branches of groups headquartered in Europe, the Gulf, Asia and the Americas.
- US-parented groupsGroups using the OECD side-by-side system that still face UK domestic top-up tax.
- Groups crossing the thresholdsBusinesses growing into the €750m and £200m tests for the first time.
Reviewed by Amir Rafiei, Senior Manager, Global Tax & Transfer Pricing, TaxDigitLast reviewed
Large group tax rules at a glance
Three lines decide most of it. Find your group's size, then tap any rule for the detail.
What applies, when, and how we help
Pillar Two global minimum tax
Multinational top-up tax and domestic top-up tax- Who
- Groups with consolidated revenue of €750m or more in at least two of the previous four years. From 2026, US-parented groups can use the OECD side-by-side system, but UK domestic top-up tax still applies.
- When
- First UK returns were due by 30 June 2026 for December 2024 year ends, then 15 months after each year end.
- How we help
- Scoping, registration, jurisdictional effective tax rate modelling, transitional safe harbour testing, the GloBE information return and the UK top-up tax return.
Country-by-country reporting
OECD BEPS Action 13- Who
- Groups with consolidated revenue of €750m or more. The UK parent, or in some cases a UK entity of an overseas group, files with HMRC.
- When
- Within 12 months of the end of the period, with a UK notification by the period end.
- How we help
- Data collection templates, the UK notification, preparation of the CbC report and reconciliation to the consolidated accounts, so it can support the Pillar Two safe harbour.
Public country-by-country reporting
EU Directive 2021/2101 and Australia- Who
- Groups with revenue above €750m in two consecutive years with EU subsidiaries or branches above the size tests. Australia has a separate public regime for groups with Australian operations.
- When
- EU: financial years starting on or after 22 June 2024, published within 12 months of the year end. Australia: periods from 1 July 2024.
- How we help
- Preparing the public report and the narrative around it, consistent with the private CbC report and the accounts.
Senior Accounting Officer and tax strategy
SAO regime and published tax strategy- Who
- UK companies or groups with turnover above £200m or a balance sheet above £2bn, and UK sub-groups of large multinationals.
- When
- SAO notification and certificate each year; tax strategy published annually on the group's website.
- How we help
- Mapping tax accounting arrangements and controls, supporting the SAO through the certificate, and drafting or refreshing the published tax strategy.
Uncertain tax treatment notification
Finance Act 2022- Who
- Companies and partnerships with UK turnover above £200m or a UK balance sheet above £2bn.
- When
- Annually, for uncertain positions above £5m in corporation tax, VAT or PAYE.
- How we help
- A process to identify notifiable positions, assessment against the triggers, and preparation of the notification.
Corporate interest restriction and digital services tax
TIOPA 2010 Part 10 and DST- Who
- Interest restriction: UK groups with net interest expense above £2m a year. Digital services tax: groups with worldwide digital revenue above £500m and UK digital revenue above £25m.
- When
- Interest restriction returns within 12 months of the period end; digital services tax returns annually.
- How we help
- Group-wide calculations, elections, the interest restriction return and DST compliance.
Quarterly instalment payments
Corporation tax instalments- Who
- Large companies with taxable profits above £1.5m, and very large companies above £20m, with the limits shared across group companies.
- When
- Four instalments during and after the year, earlier for very large companies.
- How we help
- Forecasting taxable profits, instalment workings across the group and managing interest exposure.
Transfer pricing documentation and the ICTS
Master file, local file and International Controlled Transactions Schedule- Who
- Groups of €750m or more keep a master file and UK local file. The new International Controlled Transactions Schedule will cover most large businesses with cross-border related-party transactions.
- When
- ICTS: accounting periods beginning on or after 1 January 2027, filed with the tax return. Diverted Profits Tax moves into corporation tax for periods from 1 January 2026.
- How we help
- Transfer pricing policies, benchmarking, master and local files, ICTS preparation and year-end true-ups. Transfer pricing services
Intra-group charges and financing
Arm's length principle, TIOPA 2010 Part 4- Who
- Any group with management charges, cost recharges, royalties, distribution margins or intra-group loans and guarantees across borders.
- When
- Every period, with adjustments reflected in the tax return.
- How we help
- Pricing intercompany services, IP and finance, supporting enquiries from HMRC and overseas tax authorities, and resolving double taxation.
Off-payroll working rules
IR35- Who
- Medium and large organisations that engage contractors through personal service companies. The client decides employment status.
- When
- For every engagement, with status determination statements issued to each worker.
- How we help
- Status determination processes, contractor reviews and the payroll treatment. Payroll services
Apprenticeship levy and large payrolls
Apprenticeship levy- Who
- Employers, or connected groups, with an annual pay bill above £3m, paying 0.5% of the pay bill.
- When
- Monthly through payroll.
- How we help
- Levy allowance allocation across connected companies, benefits and expenses, and payroll compliance reviews.
Plastic packaging tax
Finance Act 2021- Who
- Businesses that manufacture or import 10 tonnes or more of plastic packaging in 12 months.
- When
- Registration once the threshold is met, then quarterly returns.
- How we help
- Registration, recycled content evidence, returns and the records HMRC expects. Import and export
Carbon border adjustment mechanisms
UK CBAM and EU CBAM- Who
- UK CBAM: importers of aluminium, cement, fertilisers, hydrogen, iron and steel above £50,000 of goods in 12 months. EU CBAM: importers into the EU, with its definitive period from 2026.
- When
- UK CBAM applies to imports from 1 January 2027, with the first annual return due 31 May 2028.
- How we help
- Assessing exposure across the supply chain, registration and the returns, working with your customs broker.
Not sure which of these apply to your group?
Send us your group structure and revenue. We will map every regime and date that applies, and quote a fixed scope.
Request a group reviewPositions as at November 2026. Thresholds and dates are set by legislation and HMRC guidance and can change; we confirm what applies to your group before any work starts.
One timetable for the whole group
Need a statutory audit or independent assurance over the same numbers? TaxDigit works in alliance with Jelveh Audit & Assurance, an independent registered audit firm. Where Jelveh is your auditor, we only provide services the FRC Ethical Standard allows.
Official sources
Thresholds and dates on this page are taken from HMRC and GOV.UK guidance and legislation. We re-check them at each Budget and whenever HMRC updates its guidance.
- Domestic Top-up Tax and Multinational Top-up Tax: detailed information (GOV.UK)
- Pillar 2 side-by-side package (GOV.UK)
- Country-by-Country reporting, HMRC International Exchange of Information Manual
- Register to send a country-by-country report (GOV.UK)
- Notification of uncertain tax treatment for large businesses (GOV.UK)
- Transfer pricing: International Controlled Transactions Schedule (GOV.UK)
- Transfer pricing records: overview, HMRC International Manual INTM450010
- Check when you must register for Plastic Packaging Tax (GOV.UK)
- Prepare for the Carbon Border Adjustment Mechanism (GOV.UK)
Frequently asked questions
Does Pillar Two apply to my group?
It applies to groups with consolidated revenue of €750m or more in at least two of the previous four years. UK domestic top-up tax can apply to the UK part of a group even where the parent is overseas or uses the side-by-side system.
Who files the country-by-country report?
Normally the ultimate parent in its own country. A UK entity may have to file with HMRC if the parent's country does not exchange the report with the UK, and every UK entity in the group must make an annual notification.
What is the International Controlled Transactions Schedule?
A new schedule of cross-border related-party transactions, filed with the corporation tax return for accounting periods beginning on or after 1 January 2027.
Do we need a Senior Accounting Officer?
Yes, if your UK companies have turnover above £200m or a balance sheet above £2bn, alone or together with other UK group companies.
Can you work with our overseas head office and auditor?
Yes. We work to group reporting timetables, with overseas advisers you appoint, and alongside your auditor. For audit itself we work in alliance with Jelveh Audit & Assurance, an independent firm.