R&D Tax Relief Deadline Approaching

R&D Tax Relief Deadline Approaching for December 2025 Year-End Companies

Businesses with a December 2025 year-end that plan to make a Research & Development (R&D) tax relief claim may need to submit a Claim Notification Form (CNF) to HMRC by 30 June 2026 in order to preserve their ability to claim relief.

The introduction of the Claim Notification requirement has added an important additional step to the R&D claims process, and many companies are still unaware that missing the deadline could prevent them from making a claim altogether.

What Is R&D Tax Relief?

R&D tax relief is a UK government incentive designed to encourage innovation and investment in research and development activities.

The scheme allows eligible companies to claim tax relief or cash credits for qualifying expenditure incurred while developing new products, processes, services, or technologies, or improving existing ones through scientific or technological advancement.

Contrary to common assumptions, R&D is not limited to laboratories or highly technical industries. Claims are regularly made by businesses operating in sectors such as:

• Manufacturing

• Engineering

• Construction

• Software development

• Food production

• Automotive

• Healthcare

• Agriculture

  
  

Projects may qualify where a company has attempted to overcome technical challenges or uncertainties that could not easily be resolved by a competent professional in the field.

Typical qualifying costs can include:

• Staff salaries

• Subcontractor costs

• Software used in development

• Consumable materials

• Utilities directly related to R&D activity

  
  

Why the Claim Notification Form Matters

HMRC introduced the Claim Notification Form as part of wider reforms to the R&D tax relief regime aimed at reducing error and fraud within the system.

In certain circumstances, companies must notify HMRC in advance that they intend to submit an R&D tax relief claim. This is done through the Claim Notification Form.

If a company is required to submit a CNF but fails to do so before the deadline, HMRC may reject the subsequent R&D claim entirely, even if the underlying R&D activity would otherwise qualify.

Who May Need to Submit a CNF?

A company may need to submit a Claim Notification Form if:

• It is making an R&D claim for the first time, or

• It has not submitted an R&D claim in one of the previous three accounting periods

For companies with a December 2025 year-end, the notification deadline is generally six months after the end of the accounting period, meaning the CNF may need to be submitted by 30 June 2026.

However, some businesses are exempt from the requirement, including companies that have claimed R&D relief successfully in recent years.

Because the rules can vary depending on filing history and company structure, businesses should seek advice early to determine whether notification is required.

What Happens After the Notification?

Submitting the Claim Notification Form does not itself create the tax relief claim. It simply informs HMRC that the company intends to submit one.

The full R&D claim is still included within the corporation tax return and must normally be submitted within two years of the accounting period end.

In addition to the CNF, most companies must also submit an Additional Information Form (AIF) before the corporation tax return containing the R&D claim is filed.

Why Businesses Should Act Early

Preparing an R&D tax relief claim often takes longer than businesses expect. Technical reports, project evidence, staffing information, and financial analysis may all be required to support the submission.

Leaving the process until shortly before the deadline can create unnecessary risk, particularly where uncertainty exists around whether a Claim Notification Form is needed.

By reviewing eligibility early, businesses can:

• Confirm whether notification is required

• Avoid missing critical deadlines

• Gather supporting evidence properly

• Maximise the value of any legitimate claim

• Reduce the likelihood of HMRC enquiries

Submit Your Claim Form Before the Deadline

The 30 June 2026 Claim Notification deadline could be a crucial date for companies with December 2025 year-ends that are considering an R&D tax relief claim.

With HMRC increasing scrutiny around R&D submissions, understanding the notification rules is now just as important as understanding whether the underlying project qualifies.

Businesses that have invested in innovation, process improvement, product development, or technical problem-solving should review their position as soon as possible to avoid losing access to valuable tax relief.

Source: Gov.uk