Program explainer

UK Research and Development Tax Relief

Corporation-tax relief for companies resolving scientific or technological uncertainty, delivered through the merged scheme and enhanced support for R&D-intensive SMEs.

Administered by HM Revenue & Customs (HMRC). Educational only, not tax advice.

For accounting periods beginning on or after 1 April 2024, most claimants use the merged R&D scheme, which works as an above-the-line expenditure credit similar to the former RDEC.

Loss-making, R&D-intensive small and medium enterprises may access enhanced support under the intensive route. The right path depends on company size, profitability, and R&D intensity.

HMRC now requires additional information to be submitted before or with the claim, and has increased compliance scrutiny, so documentation quality matters more than ever.

Who qualifies

  • UK companies subject to corporation tax that carry out qualifying R&D seeking an advance in science or technology.
  • R&D-intensive SMEs that are loss-making may qualify for the enhanced intensive support.
  • Eligibility is based on resolving scientific or technological uncertainty, not on sector.

Eligible activities

  • Projects seeking an advance in a field of science or technology by resolving uncertainty a competent professional could not readily resolve.
  • Qualifying costs typically include staff, externally provided workers, subcontractors (route-dependent), consumables, software, and certain data and cloud costs.

Typically not eligible

  • Advances in the arts, humanities, social sciences, or economics.
  • Routine work with no scientific or technological uncertainty.
  • Commercial, cosmetic, or aesthetic changes without a technological advance.

How a claim works

  1. 1

    Confirm the scheme and route

    Determine whether the merged scheme or the R&D-intensive SME route applies to your accounting period.

  2. 2

    Check pre-notification

    Establish whether you must notify HMRC of your intent to claim within the required window.

  3. 3

    Define the advance and uncertainty

    Document the sought advance and the scientific or technological uncertainty for each project.

  4. 4

    Compile the additional information form

    Prepare the project and cost breakdown HMRC now requires alongside the CT600.

  5. 5

    Submit and retain support

    File with the return and keep evidence ready for HMRC compliance checks.

What to document

  • Project narratives identifying the advance sought and the uncertainty resolved.
  • Cost analysis by category with apportionment for partial R&D staff.
  • Records of subcontractor and externally provided worker arrangements.
  • Evidence supporting data, cloud, and software cost inclusion.

Common pitfalls

  • Missing pre-notification and losing the ability to claim.
  • Framing commercial progress instead of a scientific or technological advance.
  • Incomplete additional information forms triggering delays or rejections.
  • Underestimating the current level of HMRC compliance scrutiny.

Questions to ask an advisor

  • How do you handle the merged scheme versus the R&D-intensive route decision?
  • Do you manage HMRC pre-notification deadlines for new claimants?
  • How do you prepare the additional information form and defend enquiries?
  • Is your technical narrative written with input from a competent professional in the field?

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Frequently asked

Has the UK R&D scheme changed?

Yes. For accounting periods beginning on or after 1 April 2024 most companies use the merged scheme, with a separate enhanced route for R&D-intensive loss-making SMEs. Confirm your position with an adviser.

Do I need to notify HMRC before claiming?

Some companies must submit a claim notification within a set window. Missing it can prevent a claim, so check the rule early.

What counts as qualifying R&D?

Work seeking an advance in science or technology by resolving uncertainty that a competent professional could not readily resolve.

The Credit Index is informational only and does not provide tax or legal advice. Rates, thresholds, and deadlines change; confirm the current position with HM Revenue & Customs (HMRC) and a qualified adviser before acting.