Skip to content
Unclaimed
Discovery tool, not advice. Every figure is the published rule, not a decision on your case.
Tax credits

R&D tax relief (merged RDEC scheme and Enhanced R&D Intensive Support)

Status

Status not published

Claimed with the Corporation Tax return; normally within two years of the end of the accounting period. Advance notification is required for first-time and lapsed claimants within six months of the period end.

Open now
Amount
Not published

Merged RDEC scheme gives a 20% above-the-line credit on qualifying R&D expenditure. Loss-making R&D-intensive SMEs (qualifying R&D at least 30% of total expenditure) can instead claim Enhanced R&D Intensive Support - an extra 86% deduction and a 14.5% payable credit.

Funder

HM Revenue and Customs

public · national

Deadline: Open all year — Claimed with the Corporation Tax return; normally within two years of the end of the accounting period. Advance notification is required for first-time and lapsed claimants within six months of the period end.

Your odds
Not published

This funder does not publish a success rate. We rank it using the rate observed across similar programmes and label it as an estimate rather than implying we know.

Effort
moderate

Moderate — a form and supporting documents.

Who can apply

The most widely used non-dilutive funding in the UK for R&D startups. Note grant funding can affect subsidy treatment - take advice if you also hold an Innovate UK grant.

How to apply

  1. Submit a claim notification form to HMRC within 6 months of the accounting period end if you are a new or lapsed claimant
  2. Prepare the Additional Information Form detailing projects and costs
  3. Include the claim in the CT600 Corporation Tax return
  4. HMRC processes; payable credits typically take weeks to months

What you will need

Related reading: How grant deadlines actually work · R&D tax credit vs. grant: the difference that changes your claim

Apply on the funder's site

Source. https://www.gov.uk/guidance/corporation-tax-research-and-development-rd-relief · not human-checked

Verified on 14 August 2026

Source: www.gov.uk

Similar programmes

Enterprise Investment Scheme (EIS)

Open continuously

HM Revenue & Customs

Seed Enterprise Investment Scheme (SEIS)

Open continuously

HM Revenue & Customs

Enhanced R&D intensive support (ERIS) for loss-making R&D intensive SMEs

Open continuously

HM Revenue & Customs

Merged R&D expenditure credit scheme (merged RDEC)

Open continuously

HM Revenue & Customs

Patent Box

Open continuously

HM Revenue & Customs

R&D expenditure credit (RDEC) for accounting periods beginning before 1 April 2024

Closed for now

HM Revenue & Customs

Paid, separate from Unclaimed

Want a human to review your application?

Involve Consulting can help — a paid expert-review service run by the same person behind Unclaimed, entirely separate from this free check. A flat fee, agreed up front; never a cut of what you receive.

Talk to Involve Consulting