Claim notification checker: are you out of time?

For accounting periods beginning on or after 1 April 2023, first-time claimants, and companies whose last claim was more than three years before the last date of the notification period. There are exceptions where HMRC removed a claim. If you must notify and you do not, the claim for that period is invalid.

It runs from the first day of the period of account to six months after its end. For a period ending 31 December 2024, the deadline is 30 June 2025. The checker works out the dates from the period start and end dates you enter. You can change the dates to test different periods.

You must notify if your last R&D claim was more than three years before the last date of the notification period. HMRC's example is a period ending 31 December 2024, with the notification deadline of 30 June 2025: if the last claim was made before 30 June 2022, notification is required.

The checker covers two. One is where HMRC removed a previous claim. The other is where HMRC received an amendment on or after 1 April 2023 for a period that began before 1 April 2023. In those cases notification may be required even if you claimed within the last three years.

The claim for that period is invalid. That is why the checker shows the deadline, the days remaining and a warning if it has passed. If it has, do not assume the claim is lost: speak to us about whether the return route or any other option applies. Acting early avoids the problem altogether.

Possibly. A company that has claimed before, but more than three years ago or under an exception, can instead make the claim in its company tax return or an amended return, if HMRC receives it by the notification deadline. The checker flags this option where it may apply. The details matter, so check before relying on it.

HMRC's guidance does not say that first-time claimants can. The return alternative is described for companies that have claimed before. For a first claim, assume that you must notify, and speak to us if the deadline is close. This is a point where the guidance leaves a gap, and we do not fill it with assumptions that could cost you the claim.

The company's UTR, the main senior internal R&D contact, all agents, the period dates and a high-level summary of the planned activities. It is made online, and HMRC advises saving a copy before you submit it. The checker does not submit anything. You will need the details to hand before you start the online form.

Because HMRC requires every agent involved in the claim to be identified. The same applies on the additional information form, where every agent who advised, analysed costs, wrote technical reports or filed must be named. Being open about who is acting is a basic requirement, not a formality. It also applies to white-label arrangements.

No. The notification is a short advance notice, made within six months after the period ends, in the circumstances above. The additional information form is detailed and mandatory for all claims since 8 August 2023, and is submitted before or on the same day as the company tax return. Both must be done correctly.

No. Notification applies to accounting periods beginning on or after that date. For earlier periods, the rules on time limits and amendments apply instead, so use our claim time-limit checker. The notification checker will tell you when a date you enter falls outside its scope. We would rather the tool declined to answer than gave you a wrong one.

The window is tied to the period of account, from its first day to six months after its end, so it moves with the end date. For unusual or long periods, check the exact dates with us. Do not rely on the checker alone when the period is not a standard 12 months.

The first and last day of the period of account, and for a previous claim, the date HMRC received it. It trusts what you enter, so check those dates against your accounts and your records. If you are not sure when a past claim was received, the safe course is to assume that you must notify.

Do not file anything yet. Tell us the dates and what has already been done. We will check whether an exception or the return route applies, and what the position is for the period and for future periods. For future periods, we recommend diarising the notification dates. Acting quickly always helps.

No. It only covers the notification step. A valid claim also needs a project that meets the R&D definition, qualifying costs, the additional information form and a claim made in time. The checker is a prompt to act, not a clearance. Think of it as one box ticked on a longer checklist, not as the whole checklist.