R&D Tax Relief in the UK in 2026: Is It Still Worth Claiming?

R&D tax relief is still available in the UK in 2026, but it is no longer something businesses should treat as a quick year-end tax exercise. The rules have changed, HMRC scrutiny has increased, and a claim that would once have passed with a light-touch explanation may now be challenged if the evidence is weak.

So, is R&D tax relief still worth it?

For many companies, yes. If your business is genuinely trying to solve scientific or technological uncertainty, the relief can still improve cash flow, reduce Corporation Tax, or generate a payable credit. But the value of a claim now depends heavily on three things: whether the work really qualifies, whether the correct scheme is used, and whether the claim is supported by clear records.

This guide explains what UK companies should think about before making an R&D claim in 2026.

What Counts as R&D for Tax Purposes?

For tax purposes, R&D is not simply “doing something new for your business”. A project must aim to achieve an advance in science or technology and must involve scientific or technological uncertainty.

That means the key question is not: “Did we improve our product, system, or process?”

The better question is: “Was there a scientific or technological problem that a competent professional could not readily solve using existing knowledge?”

Examples may include:

• developing a new or improved manufacturing process where existing methods do not achieve the required tolerance, speed, safety, or reliability;

• creating software that goes beyond routine configuration and involves technical uncertainty around architecture, performance, integration, security, or scalability;

• testing new materials, formulations, devices, or systems where the outcome is uncertain;

• improving an existing product in a way that requires genuine experimentation rather than standard engineering or design work.

Routine upgrades, cosmetic changes, commercial research, market testing, and general business improvements will usually not be enough on their own.

What Changed for R&D Tax Relief in 2026?

The biggest change is that most companies are now dealing with the newer R&D regime for accounting periods beginning on or after 1 April 2024.

Instead of the old SME and RDEC schemes applying in the same way, companies now generally look at:

1. the merged R&D expenditure credit scheme; or

2. Enhanced R&D Intensive Support, often called ERIS, for qualifying loss-making R&D-intensive SMEs.

The merged scheme works as an above-the-line taxable credit. This means the credit is brought into account as taxable income and then used against Corporation Tax or potentially paid to the company, subject to the relevant rules and caps.

ERIS is more targeted. It is designed for loss-making SMEs with high R&D intensity. These businesses may be able to access a more generous result, but only if they meet the detailed conditions.

In 2026, the question is not just “Can we claim R&D?” It is also “Which regime applies, and have we followed the process correctly?”

What Should Businesses Think About Before Claiming?

1. Can You Clearly Explain the Advance?

A strong R&D claim starts with the technical story. HMRC will want to understand what advance was sought, why it was difficult, and how the company tried to resolve the uncertainty.

Avoid vague phrases such as “we developed an innovative platform” or “we improved efficiency”. Instead, explain the specific technical barrier. What was unknown? What alternatives were tested? Why was the solution not obvious?

The strongest input usually comes from developers, engineers, scientists, product leads, technical directors, or other competent professionals involved in the work.

2. Are You Using the Correct R&D Scheme?

For 2026 claims, it is important to check the accounting period start date. For accounting periods beginning on or after 1 April 2024, the merged scheme and ERIS are usually the key regimes to consider.

Using the wrong scheme can lead to incorrect calculations, delays, amendments, or claim rejection. This is especially important for SMEs that previously claimed under the old SME rules and may assume the process is the same.

3. Have You Submitted the Additional Information Form?

The Additional Information Form is now a critical part of the R&D claim process. It must be submitted before, or on the same day as, the Company Tax Return. If it is submitted on the same day, it should go in first.

This form is not just an admin step. It requires information about the projects, qualifying costs, technical uncertainties, and people involved. Businesses should prepare it carefully and make sure it matches the figures in the tax computation and CT600.

4. Do You Need to Notify HMRC Before Claiming?

Some companies must notify HMRC in advance that they intend to make an R&D claim. This can apply to first-time claimants or companies that have not claimed recently.

The notification deadline can be easy to miss because it comes before the normal Corporation Tax filing deadline. If your company is considering an R&D claim, check the notification position early rather than waiting until the accounts are finalised.

5. Are Your Costs Actually Qualifying Costs?

Not all innovation-related costs qualify. Businesses should review costs by category and make sure they relate directly to qualifying R&D activity.

Common areas to review include:

• staff costs and PAYE/NIC;

• externally provided workers;

• subcontracted R&D;

• software and cloud costs;

• consumables;

• data licences used in R&D;

• restrictions on overseas expenditure;

• time apportionment for staff working partly on R&D and partly on non-R&D work.

A common mistake is to claim whole project costs when only part of the project involved qualifying R&D.

6. Do You Have Evidence?

HMRC is increasingly focused on evidence. A claim is much stronger when it is supported by records created during the project, not reconstructed long after the event.

Useful evidence may include:

• project plans and technical specifications;

• development logs;

• test results;

• failed prototypes;

• design notes;

• Git commits or ticketing system records;

• meeting notes;

• staff time records;

• correspondence discussing technical problems;

• records of trials, iterations, and decision points.

The aim is to show not only that the company spent money, but that it spent money trying to resolve qualifying scientific or technological uncertainty.

Common R&D Claim Risks in 2026

Several issues can increase the risk of HMRC enquiry or rejection:

• treating commercial uncertainty as technical uncertainty;

• using generic or copied technical narratives;

• claiming for the whole product rather than the specific R&D elements;

• poor alignment between the Additional Information Form, CT600, CT600L, and tax computation;

• missing the claim notification deadline;

• submitting the Additional Information Form after the CT600;

• including overseas subcontractor or worker costs without checking the restrictions;

• assuming that a previous successful claim means future claims will automatically qualify;

• relying on estimated staff time with no supporting records;

• failing to involve a competent professional in preparing the technical explanation.

The safest approach is to prepare the claim as though HMRC will ask questions. If the claim is enquiry-ready, the business is in a far stronger position.

Practical Checklist Before Making a 2026 R&D Claim

Before submitting an R&D claim, ask:

1. Does the project seek an advance in science or technology?

2. What specific uncertainty was the company trying to resolve?

3. Would a competent professional agree that the answer was not readily available?

4. Which accounting period does the expenditure belong to?

5. Which scheme applies: merged scheme or ERIS?

6. Do we need to submit a claim notification?

7. Has the Additional Information Form been prepared and submitted at the right time?

8. Do the figures match across the tax computation, CT600, CT600L, and supporting form?

9. Have we excluded non-qualifying costs?

10. Do we have contemporaneous evidence to support the technical narrative and cost apportionment?

If the answer to any of these questions is unclear, the claim should be reviewed before submission.

Disclaimer: This article is for general information only and should not be treated as tax advice. R&D tax relief rules are detailed and fact-specific, so companies should seek professional advice before making a claim.

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