HMRC’s Advance Tax Certainty Service (ATCS) goes live on 1 July 2026 — nine days from now. If your business is planning a major UK capital investment of £1 billion or more, this is potentially the most important tax development of the year. Expressions of interest have been open since 1 June, and if you haven’t already engaged, you need to move immediately.
This post sets out what the service is, who qualifies, exactly how the process works, and the seven action points every CFO overseeing large infrastructure, energy, real estate or manufacturing projects should be taking right now.
What the Advance Tax Certainty Service Actually Does
The ATCS provides a binding clearance from HMRC on how the UK tax rules apply to a specific major investment project — issued before you file the relevant tax return and, ideally, before the final investment decision is taken. The clearance is unilaterally binding on HMRC: if you reflect HMRC’s view in your return, they cannot subsequently open an enquiry or take a contrary position. It is not binding on you — you can still take a different position, but if you do, HMRC will open an enquiry and you will likely trigger the Uncertain Tax Treatment (UTT) legislation.
The statutory basis is Part 8 of the Finance Act 2026, enacted earlier this year. HMRC published its internal manual and supporting guidance in May and June 2026 ahead of the July launch.
Who Qualifies: The £1 Billion Threshold
The entry threshold is £1 billion of qualifying UK project expenditure over the lifetime of the project. This is not turnover, not enterprise value — it is capital deployment into the UK.
Qualifying expenditure includes:
- UK expenditure on tangible assets (plant, machinery, infrastructure)
- UK expenditure on intangible assets (software, licences)
- Goods and services used or consumed in the UK or UK continental shelf
It excludes financing costs and pure equity investment (so M&A transactions or share buybacks won’t qualify on their own). The expenditure must be on a new initiative — not ongoing, ordinary business activity. Engineering services provided by overseas contractors can count, provided they are clearly attributable to the specific UK project.
Where a project is staged, HMRC will take a pragmatic view: if only Phase 1 has board approval, projected costs of subsequent phases can still be counted toward the £1 billion threshold. For joint ventures or consortia with no single controlling entity, one nominated qualifying person may apply on behalf of the group.
Both UK-resident and non-UK-resident entities investing in the UK are eligible. Foreign-owned groups investing in UK manufacturing, energy or infrastructure have equal access.
Tax Coverage: Wide, but Not Unlimited
A clearance can cover uncertainties across Corporation Tax, VAT, Stamp Duty Land Tax, Income Tax, PAYE regulations and the Construction Industry Scheme. For a major infrastructure or energy project, that is likely to cover the bulk of your material tax risks.
What ATCS will not cover:
- Transfer pricing — the existing Advance Pricing Agreement programme remains the route for those matters
- Accounting treatment of transactions
- Matters involving overseas tax authorities
- Draft legislation not yet enacted
- Main purpose or motive tests
- Asset valuations
- Matters already included in a filed tax return
HMRC will also refuse clearances where they cannot provide certainty within the 90-day window, or where they conclude the applicant’s critical assumptions cannot be reliably maintained.
The Process Step by Step
The HMRC internal manual sets out a structured six-stage process:
- Expression of Interest (EOI) — email advancetaxcertainty@hmrc.gov.uk or your Customer Compliance Manager. During the first year, HMRC will triage EOIs by complexity, urgency and breadth across tax regimes. Not every EOI will progress to a full application. Priority goes to cases with the highest level of tax uncertainty and commercial urgency.
- Early engagement meeting — HMRC aims for this within 10 working days of contact. Use it to pressure-test eligibility and scope before investing in a full application.
- Formal clearance application — must be submitted no later than 60 working days before the filing date of the first return which will include the transaction. The application must include an official business plan, the applicant’s own analysis of the tax treatment, and supporting factual evidence.
- Scoping and planning meeting — within 21 working days of application, HMRC and the applicant agree the scope of what the clearance will cover.
- HMRC evaluation — reviewed by a clearances approval board drawing on policy, operations, legal and subject matter experts. HMRC aims to issue clearance within 31 working days of the scoping meeting, or 49 working days from receipt of a complete application.
- Clearance issued — sets out scope, duration (up to five years, renewable for a further five), key facts relied on, and ongoing compliance assumptions.
Post-Clearance Obligations: Where CFOs Are Most at Risk
This is the section most commentary glosses over. Once a clearance is in place, it does not run on autopilot. As KPMG’s analysis notes, the ATCS process places a significant onus on applicants to establish and maintain robust internal governance frameworks.
Specifically:
- Annual self-monitoring of clearance conditions is required. HMRC may request copies.
- Material changes must be reported promptly. Failure to do so may render the clearance invalid and trigger a £5,000 penalty.
- False or misleading statements to HMRC in connection with a clearance carry a £10,000 penalty for careless errors and higher for deliberate ones.
- HMRC may revoke a clearance unilaterally if information provided proves false or if subsequent statute or binding case law changes the applicable tax treatment.
A clearance is not a permanent shield. It is a live document that requires active stewardship. Large projects with multi-year delivery phases will need a designated internal owner for ATCS compliance — not just the tax team that secured the clearance at the outset.
The Broader Context: Why This Exists
The ATCS emerged from a recognised problem: UK tax uncertainty was acting as a drag on large capital investment decisions, particularly in energy transition, infrastructure and manufacturing. The government’s consultation on advance tax certainty for major projects identified that the existing non-statutory clearance route was too slow, too narrow and too uncertain in itself to give investors the confidence they needed at the point of final investment decision.
The result is a statutory service — binding on HMRC, with a committed timeline, and a governance structure that gives institutional investors something they can put in front of an investment committee. This matters particularly for:
- Offshore wind and nuclear energy projects
- Data centre and semiconductor manufacturing investments
- Large-scale real estate development with complex CIS and SDLT structuring
- Cross-border infrastructure joint ventures
- PE-backed UK platform businesses undertaking major capital programmes
The government has confirmed it will review performance after 12 months and may lower the £1 billion threshold — so businesses below that level should watch this space.
Seven CFO Actions Before 1 July 2026
- Audit your investment pipeline now. Identify every capital project with £1 billion or more of qualifying UK expenditure over its lifetime. If you’re close to the threshold, include projected phase costs.
- Submit your Expression of Interest immediately. Email advancetaxcertainty@hmrc.gov.uk or contact your CCM before 1 July. In the first year, HMRC is triaging EOIs — late submissions risk missing the queue.
- Map your material tax uncertainties. HMRC prioritises cases with the highest uncertainty. Prepare a clear, ranked list of the tax issues that are genuinely unresolved — Corporation Tax capital allowances treatment, VAT on mixed-use assets, CIS obligations, SDLT on phased acquisitions.
- Prepare your business plan documentation. The formal application requires an authorised business plan showing project spend, timeline and investment decision dates. If your board papers don’t already contain this, commission it now.
- Assign an ATCS owner in the finance function. This is not a one-and-done exercise. Post-clearance monitoring, annual self-certification and change notification require a named internal owner. That person needs to understand both the project and the clearance terms.
- Coordinate with your external advisers early. The 60-working-day lead time before return filing means you cannot start this process when you’re preparing accounts. Firms including Deloitte and BDO have already published commentary — engage your advisers on structuring the application.
- Note what ATCS does not cover. Transfer pricing uncertainty still needs an Advance Pricing Agreement. Run both tracks in parallel if your project has material intercompany financing or intra-group services.
The Bottom Line
The Advance Tax Certainty Service is one of the more genuinely investor-friendly tax policy developments of recent years. Binding clearance, a committed 90-day timeline, and statutory force — that is a material improvement on what existed before. For CFOs overseeing billion-pound UK investment programmes, the question is not whether to engage, but how quickly you can get your EOI in the door.
The window opens on 1 July. HMRC will not hold capacity indefinitely for late movers.
Mark Hendy is a PE-facing CFO consultant at Tanous Limited. If you are assessing a major UK investment project and need independent advice on ATCS eligibility, tax structuring or the clearance application process, get in touch.