Certain claimants with accounting periods beginning on or after 1 April 2023, are required to inform HMRC in advance that they intend to make a claim for research and development (R&D) tax relief. Claims must be made no later than six months from the end of the accounting period to which the claim relates. More information and examples are available on GOV.UK.  

Companies filing R&D claims on or after 8 August 2023 will also need to file an additional information form before, or at the same time as, the CT600. The original intention was that this form would apply to claims for accounting periods starting on or after 1 April 2023. This was then moved to any claims filed on or after 1 August 2023. It will now apply in respect of any claim filed on or after 8 August, regardless of the accounting period to which the claim relates. For example, a company filing a claim on 8 August 2023 for the year end 30 September 2022 will now have to submit an additional information form. More information is available at GOV.UK. 

Both requirements will not be enforced until 8 August 2023 – the date that the regulations specifying the information to be provided come into force. The details to be provided in a claim notification are contained in Sch 1. The details to be provided on the additional information form are in Sch 2. 

Read more on R&D: 

• Research and development | Tax | ICAEW