Section 1054A | Requirement to make a claim notification
From legislation.gov.uk
(1)A company may not make a claim under section 1054(2) (an “R&D tax credit claim”) after the end of the claim notification period unless—
(a)the company has made an R&D claim during the period of three years ending with the last day of the claim notification period,
(b)the company makes a claim notification in respect of the R&D tax credit claim within the claim notification period, or
(c)the accounting period in respect of which the R&D tax credit claim is made falls within the same period of account as another accounting period in respect of which the company has made an R&D claim or a claim notification.
(2)For the purposes of subsection (1)(a) ignore any R&D claim for an accounting period beginning before 1 April 2023 that is included in the company’s company tax return only by virtue of an amendment made on or after that date (see paragraph 83B(2) of Schedule 18 to FA 1998).