Taxing commitments: Are promises in the Corporate Tax Roadmap holding up?

What is the Corporate Tax Roadmap?

Before I joined the CIOT in November 2025, I spent many years working in practice managing a portfolio of companies that ranged from small owner-managed businesses to large multinational corporate groups. Despite their differences, all my clients shared one common requirement: filing a corporation tax return annually. Although in theory this process should be straightforward, it was rarely so in reality. Complexity could creep in for many reasons – for example the application of intricate corporate interest restriction and loss relief rules to one-off business transactions, the interaction of corporation tax rules with accounting standards and simply managing frequent rule changes (for example around capital allowances).

Recognising the need for a steady tax environment for businesses to promote ‘investment, innovation and growth’, the (then) new Government announced the Corporate Tax Roadmap at the 2024 Autumn Budget. It highlighted three taxpayer priorities for the corporation tax system: predictability, stability and certainty.

A quick review suggests the roadmap contained 31 separate commitments. The major ones included:

• the headline corporation tax rate will be capped at 25%;
• retention of the small profits rate and marginal relief;
• the maintenance of core structural features of the corporate tax system such as loss reliefs and the UK’s capital allowances framework, including permanent full expensing and the Annual Investment Allowance (AIA);
• maintaining the generosity of Research and Development (R&D) reliefs whilst improving the administration of the scheme and introducing advanced certainty procedures;
• keeping the Patent Box in place and preserving the current approach to intangible fixed assets; and
• a new process to give investors in major projects increased advance certainty on the tax treatment that will apply.

While emphasising stability, the roadmap acknowledged that targeted reform may be necessary to keep the system dynamic and competitive. It announced a programme of consultations in specific areas to help take forward potential reforms.

Following on from confirmation that Making Tax Digital for corporation tax would be scrapped, the roadmap also committed to providing further updates on HMRC’s plans for modernising the corporation tax system.

Where are we now?

In the remainder of this article, I will focus on what progress has so far been made against the roadmap’s priorities through the lens of UK companies and groups (my heartland). There were, of course, also a number of commitments focused on international corporation tax issues including transfer pricing, diverted profits tax, Pillar One and Pillar Two which I am not going to cover here.

Predictability

Action against the commitment to predictability ‘by confirming the major features of the corporation tax regime’ can be summed up quite quickly – so far, the headline corporation tax rate has been maintained at 25% and there have been no changes to the small profits rate of 19% either. Along with the Patent Box regime, R&D relief (under the merged scheme that came into effect in April 2024) also remains in place.

When it comes to capital allowances, full expensing (i.e. first-year allowances of 100% on qualifying main rate plant and machinery and 50% on special rate plant and machinery) and the AIA (100% first-year relief on the first £1m of qualifying plant and machinery expenditure per annum) are also untouched.

The intention to consider full expensing for assets acquired for leasing or hire has resulted in the announcement within the 2025 Autumn Budget of a new 40% first-year allowance. This allowance will apply to assets utilised in leasing, as well as qualifying expenditure by unincorporated businesses, effective from 1 January 2026. These changes reflect the roadmap commitment to provide additional incentives for investment but for now fall short of full expensing, one assumes because of fiscal constraints.

Moving forward, any evaluation of predictability will rely on a commitment not to make changes to major features of the regime and whether this is upheld in the long term.

Stability

For capital allowances, it has been a mixed bag. The 2025 Autumn Budget announced:

• a reduction in the writing-down allowance for main-rate assets from 18% to 14% from April 2026;
• first-year allowances for zero-emission cars and electric vehicle charging points extended by a further 12 months until April 2027.

Whilst the extension of zero-emission allowances (alongside the introduction of the new 40% first-year allowance) was a positive step, this is potentially at the cost of those companies with large legacy pool balances who will now benefit from annual writing down allowances at a reduced rate. Altering the capital allowances rates might be viewed by some as contradicting the commitment to maintain stability.

Certainty

Following consultation, the 2025 Autumn Budget confirmed that a new target advanced assurance service for R&D relief will be piloted from spring 2026, giving time for it to be refined before it is fully implemented. The pilot will be open to small- and medium-sized companies on a voluntary basis and will cover some key areas of technical uncertainty like overseas expenditure and contracted out R&D. For now, it will run alongside the existing advanced assurance mechanism that has been in place for many years but has historically experienced low uptake.

This appears to be a direct action to address the roadmap commitments to improve certainty and the user experience of R&D reliefs, whilst at the same time helping to reduce fraud and error. We await more details of the scheme – it is essential this is properly resourced and handled by well-trained staff with sufficient technical and industry expertise (both elements being equally relevant to R&D claims) to ensure it achieves the aim of reducing error in R&D claims.

In terms of other R&D commitments, the disclosure service was launched in late 2024, and late 2025 saw the Government move forward its commitment to the introduction of an R&D expert advisory panel. The panel brings together industry expertise to help HMRC understand how R&D really happens in practice and gives more certainty on the correct for businesses making R&D claims through improved HMRC guidance and communications. More time is needed to assess the benefits of these relatively new developments.

Finally, the Government has moved forward with plans to introduce the Advanced Tax Certainty Service following consultation during 2025. This will be launched in summer 2026; however, it will initially be narrowly focused on the largest projects where at least £1bn is being invested. Because the threshold is so high, it is expected that this scheme will primarily help a small group of the UK’s largest companies, albeit allowing for a targeted and well-resourced service. There remains a question about the extent of the commitment to certainty for all UK businesses in the longer term. The scheme will be reviewed after a year, and Government may consider threshold changes in future.