Claim Notification Form & R&D Tax Relief UK: Key Deadline June 30, 2025

Claim Notification Form: What UK Businesses Must Know About R&D Tax Relief Deadlines

Claim Notification Forms (CNFs) continue to be a crucial topic for businesses planning to submit an R&D tax credit claim in the UK. Understanding when a claim notification form is needed, and the importance of meeting deadlines, can make all the difference in successfully accessing R&D tax relief.

Why is the June 30, 2025 Deadline Important for R&D Claim Notification?

Most UK companies have a December financial year-end, meaning a large number of potential claimants for R&D tax credits UK will need to submit their R&D claim notification by June 30, 2025. This deadline applies to businesses with accounting periods ending December 31, 2024. Missing this date means losing the right to claim HMRC R&D tax credits for that period — and no appeals will be accepted, even after HMRC’s recent concession to reassess some claims affected by earlier incorrect guidance.

When is a Claim Notification Form Needed?

The requirement to submit a claim notification form isn’t limited to new applicants. Existing claimants may also need to file a CNF depending on the timing and method of their previous claims. Since the new rules came into effect for accounting periods starting on or after April 1, 2023, it’s vital to determine if your business or clients need to provide this notification.

What Action Should You Take?

Accountants and businesses alike should urgently review their R&D portfolios to confirm whether an R&D claim notification is required. It’s better to identify early if a notification isn’t needed or if there are no qualifying R&D projects. This proactive approach avoids missing the deadline and losing out on valuable R&D tax credits UK.

In summary:

If your company plans to make an R&D tax credit claim for the accounting period ending December 31, 2024, submitting a claim notification form to HMRC by June 30, 2025 is mandatory.

If you would like to learn more about R&D Tax and how we can support you, visit Innovation Tax Reliefs page. 

📞 Need expert advice on navigating HMRC R&D tax credits and ensuring your claim is compliant? Fill out the form on the bottom of this page for tailored support with your R&D tax relief UK claim.