Ultimate Guide to UK R&D Tax Relief 2025

Q: What are the main differences between the RDEC and ERIS schemes for UK R&D tax relief in 2025?

The RDEC (Research and Development Expenditure Credit) scheme and the ERIS (Enhanced R&D Intensive Scheme) differ in a few important ways: These schemes are designed to encourage innovation, but the best option depends on factors like your company’s size, financial situation, and how much of its resources go toward R&D.

by Adam Park | October 28, 2025

UK businesses investing in research and development (R&D) can reduce costs and boost cash flow through two key tax relief schemes in 2025: RDEC and ERIS. These schemes aim to encourage innovation by offering tax credits or deductions for eligible R&D expenses. Here’s what you need to know:

RDEC: Designed mainly for large companies, it provides a credit shown as income, which can reduce tax liabilities or result in cash payments.
ERIS: Tailored for SMEs with significant R&D activities, offering higher relief rates and cash credits for loss-making firms.
Key Updates in 2025: Stricter compliance rules, clearer definitions of qualifying activities, and refined eligibility criteria ensure the scheme supports genuine R&D efforts.
Qualifying Costs: Include staff, subcontractors, materials, software, and utilities directly related to R&D.
Claim Process: Requires detailed documentation, technical narratives, and accurate cost calculations.

These schemes are vital for businesses aiming to reduce financial risks tied to R&D projects. By maintaining thorough records and complying with HMRC’s updated rules, companies can maximise these benefits.

RDEC and ERIS Schemes Explained

The UK’s R&D tax relief system in 2025 revolves around two key schemes aimed at supporting businesses involved in innovative research and development. To make the most of these opportunities and stay compliant with HMRC, it’s crucial to identify which scheme applies to your business. Here’s a closer look at both schemes.

RDEC Scheme Overview

The Research and Development Expenditure Credit (RDEC) is tailored primarily for large companies, though certain SMEs receiving state aid can also qualify. Unlike traditional tax deductions, RDEC appears as income on a company’s profit and loss accounts.

Under this scheme, businesses can claim credit for eligible R&D costs. This credit can reduce their tax liability or, if it exceeds the amount owed, result in a cash payment. By offering this flexibility, RDEC allows companies to better manage their cash flow while recognising the value of their R&D efforts. For how R&D spend interacts with your tax bill, see is R&D tax deductible?

Enhanced R&D Intensive Scheme (ERIS) Explained

The Enhanced R&D Intensive Scheme (ERIS) is specifically designed for SMEs that prioritise R&D in their operations. To qualify, businesses must demonstrate that their R&D expenditure represents a significant proportion of their total spending. This ensures the scheme targets companies where innovation plays a central role.

ERIS offers a more generous deduction for qualifying R&D expenses. For SMEs operating at a loss, there’s also the potential to claim a payable credit. This scheme is available to UK-resident SMEs that meet both the size and R&D intensity criteria.

RDEC vs ERIS Comparison

Aspect	RDEC	ERIS
Eligibility	Mainly large companies and certain SMEs receiving state aid.	SMEs with a strong focus on R&D activities.
Size Requirement	Open to companies of any size that meet the criteria.	Restricted to SMEs under UK eligibility rules.
Method of Relief	An above-the-line credit shown as income.	A below-the-line deduction reducing taxable profits.
Benefit Realisation	Can offset tax liabilities or result in a cash payment if the credit exceeds taxes owed.	Allows loss-making SMEs to claim a cash credit in addition to enhanced relief.
R&D Intensity Requirement	No specific R&D intensity requirement.	Requires R&D to account for a significant share of total spending.
State Aid Considerations	Available even if the company receives state aid.	Not typically accessible to businesses receiving notifiable state aid.

These schemes represent the updated framework for 2025, aimed at bolstering innovation across the UK.

Eligibility and Qualifying Activities

Understanding the rules for eligibility and qualifying activities under the 2025 framework is crucial if you want to make the most of UK R&D tax relief. The updated framework lays out clearer criteria, helping businesses identify the right scheme and determine which activities qualify as R&D.

Who Qualifies for R&D Tax Relief

Eligibility depends on the scheme you apply for - RDEC or ERIS - but one requirement is consistent: your business must be subject to UK Corporation Tax. In other words, if your company pays Corporation Tax on its profits, you may qualify for R&D tax relief.

Limited Companies: If you're a private limited company (Ltd) or a public limited company (PLC), you are subject to Corporation Tax, making you eligible to claim.
Companies Limited by Guarantee: Organisations like research institutions or technology transfer companies can claim R&D tax relief if they have a Corporation Tax liability.
Group and Subsidiary Companies: Only the group member paying Corporation Tax on R&D profits can claim. Similarly, if you're part of a partnership, corporate partners paying Corporation Tax may claim their share of R&D costs.
Limited Liability Partnerships (LLPs): While LLPs are typically tax-transparent, corporate members subject to Corporation Tax can claim for their share of the LLP's R&D activities.

Scheme-Specific Requirements

Enhanced R&D Intensive Scheme (ERIS): This scheme is designed for loss-making SMEs that meet specific R&D intensity thresholds. It supports businesses where R&D forms a significant part of their spending.
Merged Scheme: For accounting periods starting on or after 1 April 2024, most companies will fall under this scheme. By 1 April 2025, it becomes mandatory for all companies claiming R&D tax relief.

Next, let’s explore what activities HMRC considers as qualifying R&D.

What Counts as Qualifying R&D Activities

To qualify, your R&D activities must aim to advance science or technology by addressing uncertainties that go beyond standard expertise. HMRC focuses on systematic investigation that pushes the boundaries of what’s currently known.

Core Qualifying Activities

Developing New Products, Processes, or Services: This includes tackling technical challenges, such as creating new software algorithms, designing innovative materials, or introducing advanced manufacturing methods.
Improving Existing Technology: Enhancements must go beyond routine upgrades. For example, improving performance, functionality, or efficiency in a way that involves solving technical uncertainties qualifies.
Feasibility Studies: These count if they assess the scientific or technical viability of a project, rather than focusing on market research.
Prototyping and Testing: Building and testing prototypes to validate new concepts and conducting experiments to explore technical approaches are eligible.
Software Development: Activities like creating new algorithms, solving complex computational problems, or developing advanced functionality in software engineering meet the criteria.

Now that we’ve covered eligible activities, let’s look at what is excluded from claims.

What Doesn't Qualify: Restrictions and Exclusions

Certain activities, despite their importance to your business, do not meet HMRC’s criteria for R&D tax relief:

Routine Tasks: Activities like standard quality control, regular maintenance, or minor product updates are excluded because they don’t involve resolving technical uncertainties.
Market Research and Sales: While these activities are essential for growth, they don’t advance science or technology and therefore don’t qualify.
Overseas Expenditure: Costs incurred abroad can only be included if they directly relate to UK-based R&D.
Social Sciences, Arts, and Humanities: Research in these fields is excluded unless it involves clear technological advancements. Purely theoretical work without practical applications is also ineligible.
Routine Data Collection: Standard data gathering or analysis doesn’t count, but creating new analytical tools or methods might qualify.
Legal and Administrative Costs: Expenses for intellectual property protection, compliance, or general business operations are not eligible, even if they support R&D projects.

The deciding factor is whether your activities involve a systematic effort to resolve technological uncertainties and advance knowledge. Simply applying existing techniques, no matter how complex, does not meet the criteria for R&D tax relief.

How to Calculate and Claim R&D Tax Relief

Once you've identified your qualifying R&D activities, the next step is to figure out your eligible costs and navigate the claims process. Getting these details right can mean the difference between a successful claim and one that gets rejected.

Qualifying Costs and How to Calculate Them

Your R&D tax relief claim revolves around qualifying expenditure - expenses that directly relate to your R&D activities. Both the RDEC and ERIS schemes allow claims for specific categories of costs.

Staff Costs: Only claim the portion of staff costs directly linked to R&D. Using timesheets to track staff time is a practical way to ensure accuracy.
Subcontractor Costs: These can be included, but the rules vary depending on whether the subcontractor is connected (e.g., part of your group) or unconnected. Check the latest guidelines to determine the eligible proportion.
Materials and Consumables: Items like raw materials, components, and consumables used during R&D are claimable. However, equipment or machinery typically doesn’t qualify unless it is consumed or transformed as part of the R&D process.
Software Costs: Software used directly in R&D projects is eligible, including specialist licences, cloud computing services, and other software purchased specifically for research purposes.
Utilities: Proportional costs for utilities like electricity and water used in R&D can also be claimed.

Calculating Your Benefit

How you calculate your benefit depends on your company’s tax position and the scheme you’re using:

RDEC Scheme: This provides a tax credit based on a percentage of qualifying R&D costs. If your company is profitable, the credit can reduce your Corporation Tax bill. If the credit exceeds your tax liability, you may be able to carry it forward or, in some cases, receive a cash payment.
ERIS Scheme: For loss-making companies, the benefit often comes as a cash credit, calculated as a percentage of your qualifying R&D costs. For example, a software company would apply the credit to its total eligible R&D expenditure. The exact benefit depends on your circumstances and the current rules.

Once you’ve calculated your eligible costs, follow the steps below to make your claim.

Step-by-Step Claim Process

The claims process includes specific notifications and deadlines. Here’s how to proceed:

Step 1: Advance Notification
Some claims require advance notification. You may need to inform HMRC of your intent to claim R&D tax relief before submitting your Corporation Tax return. Check HMRC’s latest guidance for deadlines.

Step 2: Gather Supporting Documentation
Keep detailed records throughout your R&D projects. This includes project logs, technical reports outlining the challenges and advancements, financial records linking costs to activities, and timesheets documenting staff involvement.

Step 3: Prepare Your Technical Narrative
Create a technical narrative explaining the technological advancements you aimed for, the uncertainties you faced, how you addressed them, and the outcomes of your work. HMRC expects this level of detail.

Step 4: Complete the Claim Calculation
Categorise your costs accurately and apply the relevant relief rates using HMRC’s prescribed formats. Ensure your calculations align with your accounting records.

Step 5: Submit Your Claim
Include your R&D claim with your Corporation Tax return and submit it by HMRC’s deadline to avoid delays.

Step 6: Respond to HMRC Enquiries
HMRC may request additional evidence or clarification. Be ready to provide further documentation or explanations to support your claim.

Compliance Tips and Best Practices

Staying compliant with R&D tax relief rules requires careful planning and organisation:

Document in Real-Time: Keep daily project logs detailing activities, challenges, and solutions.
Separate R&D Costs: Use dedicated cost codes in your accounting system to ensure accuracy and maintain a clear audit trail.
Review Eligibility Regularly: As projects evolve, review them periodically to confirm that you’re capturing all qualifying activities and excluding ineligible ones.
Leverage Technical Expertise: Have someone with technical knowledge review your claim, especially when explaining the scientific or technological aspects.
Track Staff Time Accurately: Maintain detailed records of how staff time is allocated to R&D to justify employment cost claims.
Align Projects with Accounting Periods: Plan your R&D projects to fit within your accounting periods, allowing enough time for documentation and claim preparation.

Case Studies and Expert Advice

Learning from real-world examples and expert insights can make a big difference when preparing your R&D tax relief claim under the updated 2025 rules. By understanding how other businesses have successfully navigated these changes, you can avoid common mistakes and ensure your claim is as effective as possible.

Successful R&D Claims: 2025 Case Studies

These examples highlight how companies from different industries have approached compliance and calculations under the new regulations:

Manufacturing Innovation Case
A mid-sized manufacturing company in the West Midlands successfully claimed R&D tax relief through the ERIS scheme. Their project focused on developing an automated quality control system using machine learning to improve defect detection. By keeping detailed records and demonstrating a clear, systematic approach to tackling technological challenges, the company passed HMRC’s review without issues.

Software Development Success
A fintech startup based in London secured R&D tax relief through RDEC after creating blockchain-based payment verification technology. They maintained clear timesheets to distinguish between qualifying R&D work and routine software maintenance. Their technical narrative focused on overcoming specific cryptographic challenges, which helped HMRC clearly see the innovative aspects of their project.

Green Technology Breakthrough
An energy company in Scotland successfully claimed R&D tax relief for its work on next-generation solar panel efficiency technology. By documenting their experimental processes and highlighting the technological uncertainties they faced, the company was able to meet the updated rules and substantiate their claim effectively.

Expert Tips for Maximising Your Claim

Drawing from experience, here are some practical strategies to help you succeed:

Highlight Technological Challenges, Not Just Results: Focus on the scientific or technological problems you solved, rather than the commercial outcomes of your project.
Maintain Detailed Records: Keep thorough documentation, including project logs, meeting notes, and experimental data, to support your claim.
Separate R&D from Routine Work: Clearly identify and document the qualifying R&D activities, ensuring they are distinct from regular operational tasks.
Collaborate with Your Accountant: Share all relevant documentation early on to ensure your claim aligns with HMRC’s expectations.
Prepare for HMRC Enquiries: Many claims are reviewed by HMRC, so organise your records and make sure key technical staff are available to respond to any questions.

These strategies can help you navigate the complexities of the 2025 rules and strengthen your claim.

How Zest R&D Tax Advisors Can Help

Given the importance of detailed documentation and technical precision, expert advice can be invaluable. Zest R&D Tax Advisors provides tailored support to guide you through the updated R&D tax relief process.

End-to-End Support: From assessing your eligibility to submitting your claim and ensuring compliance, Zest offers comprehensive assistance. Their percentage-based fee structure means you only pay if your claim is successful.
Technical and Compliance Expertise: Zest works closely with your technical team to craft a strong, compliant claim narrative that meets HMRC’s requirements.
Seamless Accountant Collaboration: By partnering with your existing accountants, Zest ensures your R&D claim aligns with your broader tax strategy.
Support for Green Projects: Businesses working on environmentally beneficial initiatives can benefit from reduced fees, reflecting Zest’s commitment to sustainable innovation.
R&D Tax Relief Calculator: Zest provides an online tool to estimate your potential tax relief under both the RDEC and ERIS schemes, giving you a clear picture of the financial benefits.

With their expertise, collaborative approach, and focus on compliance, Zest R&D Tax Advisors can help you maximise your claim while staying aligned with HMRC’s updated rules.

Getting the Most from R&D Tax Relief in 2025

By 2025, the UK's R&D tax relief schemes, RDEC and ERIS, have become even more valuable for businesses aiming to innovate. To make the most of these opportunities, it’s essential to stay on top of the updated rules and maintain detailed records.

To maximise your claim, preparation is key. Companies that succeed often focus on showcasing the technological uncertainties they’ve tackled, rather than just emphasising commercial results. This aligns closely with HMRC’s focus on recognising genuine innovation and advancements in science or technology.

Keeping thorough records is another critical step. With HMRC enquiries becoming more frequent, having detailed project logs, experimental data, and timesheets can significantly strengthen your claim. Many successful businesses featured in our case studies credit their success to this level of precision and organisation.

If your work involves environmentally friendly projects, there are extra benefits to consider. Green R&D initiatives often qualify for lower advisory fees and may access additional support, making sustainable innovation even more appealing.

Zest’s percentage-based fee structure offers peace of mind by ensuring you only pay if your claim succeeds. From assessing your eligibility to ensuring HMRC compliance, their team provides expert guidance every step of the way, working seamlessly alongside your existing accountants. This approach removes financial risk while keeping the process straightforward.

FAQs

What are the main differences between the RDEC and ERIS schemes for UK R&D tax relief in 2025?

The RDEC (Research and Development Expenditure Credit) scheme and the ERIS (Enhanced R&D Intensive Scheme) differ in a few important ways:

Eligibility: RDEC is available to all UK companies liable for Corporation Tax that undertake qualifying R&D projects. In contrast, ERIS is tailored for loss-making SMEs where R&D spending makes up at least 30% of their total costs.
Tax Benefits: RDEC offers a taxable credit equal to 20% of qualifying R&D expenditure. ERIS provides eligible SMEs with an extra 86% deduction on qualifying costs and a payable tax credit of up to 14.5% on their surrenderable loss.
Overseas Costs: Starting 1 April 2024, both schemes will exclude most overseas R&D costs, except in cases where specific exceptions are met.

These schemes are designed to encourage innovation, but the best option depends on factors like your company’s size, financial situation, and how much of its resources go toward R&D.

What steps should businesses take to comply with the updated R&D tax relief rules in 2025?

To keep up with the updated R&D tax relief rules coming in 2025, businesses will need to pay attention to some key changes. These include the combined RDEC scheme, the requirement to submit an Additional Information Form (AIF), and tighter oversight from HMRC. Maintaining precise and thorough records of all qualifying R&D activities and related expenses will be more important than ever.

It's worth noting that only companies liable for UK Corporation Tax can claim R&D tax credits, so confirming eligibility is a must. By regularly reviewing internal procedures and consulting with specialists, businesses can optimise their claims while staying compliant with the new regulations.

What R&D activities qualify for tax relief under the 2025 UK schemes?

To be eligible for R&D tax relief under the 2025 UK schemes, your activities must aim to achieve an advance in science or technology by addressing a specific scientific or technological uncertainty. This means the work should go beyond day-to-day tasks, contributing to the broader knowledge or capabilities in the field - not just serving your company’s immediate interests.

Eligible projects typically involve systematic research or experimentation, carried out with a structured plan. The focus should be on innovation, such as creating new products, processes, or services, or making significant improvements to existing ones. Routine updates or minor tweaks that don’t address genuine uncertainties are unlikely to meet the criteria.