How soon after my business’s accounting period has ended should an R&D claim be submitted?

How soon after my business’s accounting period has ended should an R&D claim be submitted?

There are a few key timing considerations for submitting an R&D tax credit claim after your business’s accounting period has ended:

· The R&D claim can only be submitted after your company accounts have been prepared and finalised. Subsequently, you can make your claim for R&D tax relief in your Corporation Tax return or amended return.

· Mandatory additional information required to make an R&D claim: After 8 August 2023, HMRC will require R&D claimants to fill an ‘Additional information form’ (AIF). This form must be completed and submitted to HMRC before your company’s Corporation Tax return for the period is submitted to HMRC. Failure to do so will nullify the claim.

· How far back can I claim? Claims can technically be submitted up to 2 accounting periods after the period end date per HMRC guidelines. For example, if your accounting period ended on 31 December 2021, you would have until 31 December 2023 to submit an R&D claim.

· Do I need to notify HMRC about an R&D tax claim in advance? Yes – If your company is a first-time claimant or has not claimed R&D tax relief in the past three years, and your accounting period starts after 1 April 2023, you must notify HMRC of your intention to make a claim within six months of that period ending.

Changing Accounting periods:

  • Extending your R&D claim period: The accounting period can be extended beyond the normal 12-month accounting period up to 18 months. This can allow more qualifying R&D expenditure to be included within the accounting period.
  • Shortening your R&D claim period: The accounting period can be shortened to less than 12 months. This can allow expenditure to be claimed earlier, which improves cash flow.
  • HMRC must approve extended and shortened periods in advance.

Advanced assurance for SMEs:

  • Advance Assurance is a scheme provided by HMRC aimed at supporting SMEs applying for R&D tax relief. This scheme is voluntary and designed to facilitate the processing of R&D claims without additional HMRC enquiry.
  • According to HMRC guidelines, obtaining Advance Assurance acts as a validation that claims will be accepted, provided they align with what was discussed and agreed upon in the application. The Advance Assurance applies to a company’s first three R&D tax relief claims.
  • Who can apply? All SMEs are eligible to apply for Advance Assurance and as long as the company is not part of a group and none of the companies linked to the claimant entity have previously made a claim.

Get in touch with Moore R&D

Call us on:

+44 (0)20 4582 1405

Email us:


Follow us:

How did you hear about us?