The claim notification form is the requirement that quietly disqualifies claims. It is not the claim, it is a warning that a claim is coming, and a company that fails to send it in time loses the relief for that period outright regardless of how good the underlying work was. The deadline is earlier than the claim deadline and earlier than most companies expect.
The window
The claim notification period starts on the first day of the period of account and ends six months after the end of that period of account. For a company with a 31 March year end, that means the notification has to be with HMRC by 30 September the same year, while the claim itself could otherwise have been made much later. Missing it is not a penalty situation; it is a loss of entitlement for the period, which is a far more expensive outcome.
Who has to file one
Broadly, a company that has not claimed R&D relief recently. The requirement is aimed at first-time and returning claimants rather than at companies with a continuous claim history, and the precise test turns on whether a valid claim was made in a defined preceding period. Because the consequence of getting it wrong is total, the safe course for any company unsure of its recent claim history is to check the rule against its own filings rather than assume it is exempt.
It is separate from the additional information form
Two forms, two purposes, two deadlines. The claim notification comes first and says a claim is coming. The additional information form, mandatory for every claim since 8 August 2023, comes with the claim and sets out the projects and the qualifying expenditure in HMRC's required structure. A claim submitted without the additional information form is removed from the return; a claim for a period with no notification where one was required is not available at all.
Questions people ask about r&d claim notification form
When is the R&D claim notification form due?
The notification period ends six months after the end of the period of account. For a 31 March year end that is 30 September of the same year.
What happens if I miss the notification deadline?
The relief is not available for that period. It is a loss of entitlement rather than a penalty, which makes it the most expensive deadline in the R&D regime.
Is the notification the same as the additional information form?
No. The notification says a claim is coming and is due six months after the period of account ends. The additional information form accompanies the claim and has been mandatory for every claim since 8 August 2023.