R&D tax relief remains one of the most valuable Corporation Tax incentives available to UK limited companies investing in innovation. If you are asking what R&D tax relief in 2026 is, you are likely assessing how the merged scheme affects your projects, cash flow and Corporation Tax position. 

For accounting periods beginning on or after 1 April 2024, the UK operates a merged R&D scheme that replaced the previous SME and RDEC structures. The vast majority of claims made in 2026 will fall under this scheme, along with a small number that fall under the ERIS scheme – specifically designed to offer loss-making, R&D intensive companies a higher rate of tax relief. 

Understanding R&D tax relief today means knowing what qualifies, how the merged scheme operates - or whether a business qualifies for ERIS - and how to submit a claim that withstands enquiry. 

For many directors, the starting point remains the same question: what really is R&D tax relief and how does it apply to the work we do? 

When directors ask what R&D tax relief is, the answer hasn’t changed a great deal since the inception of the scheme, despite many changes to the qualification criteria over the years.

It is still the same UK government incentive that allows eligible limited companies to reduce their Corporation Tax bill or claim a payable credit for qualifying research and development activity. 

This is possible when the company seeks an advance in science or technology and incurs qualifying costs while attempting to achieve it – these costs are then submitted, along with a technical report, through the company’s Corporation Tax return as part of an R&D tax credit claim. 

Claims arise across all industries - from software development to engineering, farming to pharmaceuticals, and everything in between - where teams address genuine technical challenges.

No. R&D tax relief is not a grant. 

It operates through the Corporation Tax system. Profitable companies reduce their Corporation Tax liability. Loss making companies can receive a payable credit, subject to scheme rules. 

After an extended period of consultation, HMRC decided to bring the ‘older’ SME and RDEC schemes in line with each other, creating the ‘merged scheme’. For accounting periods beginning on or after 1 April 2024, this merged scheme applies a blend of the rules regarding qualifying R&D that used to exist across the two older schemes. 

These changes can be very impactful – for the better or worse – for claimant companies, so it’s important that directors are well informed and don’t apply outdated calculations or qualification criteria when looking at their R&D expenditure

A clear understanding of what is r&d tax relief helps frame this eligibility test correctly before reviewing individual projects. 

To qualify, a project must seek an advance in science or technology and resolve scientific or technological uncertainty. 

HMRC assesses what your team could not readily achieve at the outset using existing knowledge. An advance improves overall knowledge or capability in a field. Technological uncertainty exists where a competent professional cannot readily deduce the solution at the start of the project. 

Qualifying work can include anything technically or scientifically uncertain, such as developing new software architecture to overcome performance limits or designing manufacturing processes that existing methods cannot achieve. Routine updates, aesthetic changes, straightforward adaptations and purely commercial challenges do not qualify. 

The core test centres on genuine scientific or technological uncertainty and a structured attempt to resolve it. 

If you are reviewing current or recent projects and want an informed view on how HMRC would interpret your work through an R&D tax relief lens, a quick conversation can clarify your next steps. You can contact our team to discuss your projects in confidence before progressing to cost calculations.

Any UK limited company subject to Corporation Tax can claim if it undertakes qualifying R&D and incurs eligible expenditure. Eligibility depends on the technical substance of the work, not the sector alone.

Qualifying expenditure includes staff costs for employees engaged in R&D, externally provided workers and subcontractors, software used in development, consumable materials and specific data or cloud computing costs. 

Capital expenditure falls outside this incentive and may instead be considered under capital allowances. Clear cost allocation should link staff time and third party costs directly to R&D activities. 

Under the merged scheme, companies calculate qualifying R&D expenditure and apply the relevant expenditure credit rate within their Corporation Tax computation. 

The net benefit depends on the credit rate and the company’s tax position. Loss making R&D intensive SMEs that meet the required intensity threshold may access enhanced support through ERIS. 

Accurate cost data and alignment between the technical explanation and financial schedules remain central to a robust claim. 

Recent reforms introduced additional compliance requirements, including claim notification in certain cases and submission of an Additional Information Form. 

HMRC expects clear explanations of the technological advance sought, the uncertainties faced and the work undertaken. You can review more detailed R&D tax relief FAQs covering eligibility and documentation requirements. Generic descriptions weaken claims because they fail to explain why the solution proved uncertain. 

Structured, evidence-based submissions place companies in a stronger position if HMRC opens a compliance check. The number of these types of enquires is around 40-fold greater than pre-covid levels, with HMRC aiming to review 20% of all claims. As such, knowing your way around the legislation is essential, or just ensure that your R&D advisor includes free support in the event of a compliance check (which Easy R&D does, of course).

R&D tax relief may sit alongside other UK tax reliefs. Companies investing in plant and machinery can explore capital allowances, while certain creative or property development projects may qualify for specialist reliefs. Each scheme operates under its own legislative framework and eligibility criteria.

In 2026, what is R&D tax relief comes down to understanding a Corporation Tax incentive delivered through the merged scheme and supported by credible technical evidence. When business owners revisit what is R&D tax relief in light of the merged scheme, they are often reassessing how technical documentation and cost allocation will stand up to HMRC scrutiny. 

At Easy R&D, we support businesses that want clear eligibility decisions, accurate calculations and compliant submissions. If you are reassessing your approach under the merged scheme or preparing to submit a claim, speaking with a specialist early can provide clarity and reduce avoidable risk. You can arrange a technical eligibility discussion for a straightforward conversation about your eligibility and next steps. You can also review our recent R&D tax relief case studies to see how structured claims are presented in practice.