Tax
R&D Tax Credits Guide UK — How Small Businesses Can Claim
How R&D tax credits work for UK small businesses, what qualifies, how much you can claim, the merged scheme rules, and how to apply.
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5 min read
R&D tax credits can be worth thousands for innovative UK businesses. Here’s how to check if you qualify and how to claim.
At a Glance
| Feature |
Detail |
| What they are |
Tax incentive for companies investing in research and development |
| Who can claim |
UK limited companies paying corporation tax |
| Merged scheme rate (from April 2024) |
20% above-the-line credit on qualifying R&D spend |
| R&D-intensive SME rate |
27% payable credit for loss-making R&D-intensive companies |
| Claim deadline |
2 years after the end of the accounting period |
| How to claim |
Via corporation tax return (CT600) |
The Merged R&D Scheme (From April 2024)
| Feature |
Detail |
| Applies to |
Most companies (SMEs and large companies) |
| Credit rate |
20% of qualifying R&D expenditure |
| How it works |
Credit goes through the P&L as income, then corporation tax is paid on it |
| Net benefit (25% CT rate, profit-making) |
~15% of qualifying spend |
| Net benefit (19% CT rate, if applicable) |
~16.2% of qualifying spend |
| Loss-making companies |
Can surrender the credit for a cash payment (at a lower rate) |
R&D-Intensive SMEs
| Feature |
Detail |
| Who qualifies |
SMEs where R&D spend is 30%+ of total expenditure |
| Benefit |
Enhanced payable credit rate of 27% (for loss-making companies) |
| Why it matters |
Higher cash benefit for pre-revenue companies spending heavily on R&D |
What Qualifies as R&D?
| The project must… |
Detail |
| Seek an advance in science or technology |
New knowledge, new capability, or a new/improved product, process, or service |
| Overcome technological uncertainty |
The solution wasn’t readily deducible by a competent professional |
| Relate to your company’s trade |
The R&D must be relevant to your business (current or intended) |
| Not be routine work |
Standard engineering, cosmetic design changes, or social science don’t qualify |
What Counts as R&D
| Qualifies |
Doesn’t qualify |
| Developing new software functionality |
Routine software updates or bug fixes |
| Creating new manufacturing processes |
Implementing off-the-shelf solutions |
| Overcoming engineering challenges |
Aesthetic or cosmetic design |
| Developing new materials or formulations |
Market research |
| Improving energy efficiency through new tech |
Social science or economics research |
| Prototyping and testing |
Commercial or financial innovation |
| Failed projects (you tried but it didn’t work) |
Work where the solution was already known |
Common Qualifying Sectors
| Sector |
Example R&D activities |
| Software/tech |
New algorithms, AI/ML development, bespoke software platforms, cybersecurity |
| Engineering |
New product design, process automation, materials testing |
| Manufacturing |
Production line innovation, new materials, quality improvement |
| Construction |
Novel building techniques, structural challenges, energy-efficient design |
| Food & drink |
New recipes overcoming preservation challenges, alternative ingredients |
| Pharmaceuticals |
Drug development, clinical trials, formulation challenges |
| Agriculture |
New farming techniques, crop science, environmental innovation |
| Aerospace/automotive |
Component design, emissions reduction, lightweight materials |
Qualifying Expenditure
| Cost type |
What’s included |
| Staff costs |
Salaries, NI, pension contributions for employees working on R&D |
| Subcontractor costs |
Payments to subcontractors for R&D work (65% of cost for unconnected parties) |
| Externally provided workers |
Agency staff working on R&D (65% of cost) |
| Consumables |
Materials and utilities consumed or transformed in R&D |
| Software |
Licences for software used directly in R&D |
| Data and cloud computing |
Data licences and cloud computing costs directly attributable to R&D |
What You Can’t Claim For
| Non-qualifying costs |
| Capital expenditure (equipment, buildings) — claim via capital allowances instead |
| Patent costs |
| Land and rent |
| Production of goods and services (post-R&D) |
| Admin and support costs not directly related to R&D |
Worked Examples
Profit-Making Company
| Item |
Amount |
| Qualifying R&D expenditure |
£100,000 |
| Merged scheme credit (20%) |
£20,000 |
| Corporation tax on the credit (25%) |
-£5,000 |
| Net tax benefit |
£15,000 |
Loss-Making Company (Not R&D Intensive)
| Item |
Amount |
| Qualifying R&D expenditure |
£100,000 |
| Merged scheme credit (20%) |
£20,000 |
| Payable credit (limited by tax notional charge) |
Up to ~£16,000 cash |
Loss-Making R&D-Intensive SME
| Item |
Amount |
| Qualifying R&D expenditure |
£100,000 |
| Enhanced credit rate |
27% |
| Cash credit |
£27,000 |
How to Claim
| Step |
Detail |
| 1 |
Identify qualifying projects — what R&D did you undertake? |
| 2 |
Calculate qualifying expenditure — staff, subcontractors, consumables, software |
| 3 |
Prepare a technical report — describe the advance sought, the uncertainty, and how you tried to resolve it |
| 4 |
Complete the CT600 — fill in the R&D boxes in your corporation tax return |
| 5 |
Submit additional information form — required from August 2023 onwards |
| 6 |
Submit to HMRC — within 2 years of the end of the accounting period |
Using an R&D Adviser
| Factor |
Detail |
| Typical fee |
15–30% of the successful claim (or fixed fee: £3,000–£10,000+) |
| What they do |
Identify qualifying activities, maximise expenditure, prepare the technical report, handle HMRC queries |
| Is it worth it? |
Often yes — especially for first claims. They typically identify more qualifying spend than you’d find yourself |
| Choosing an adviser |
Look for CIOT/ATT qualifications, R&D-specific experience, no “no-win no-fee” upfront fees, transparent pricing |
HMRC Compliance and Enquiries
| Feature |
Detail |
| Additional Information Form |
Required for all claims from 1 August 2023 — must be submitted before or with the CT600 |
| HMRC scrutiny |
R&D claims are subject to increasing HMRC enquiry rates |
| Common reasons for enquiry |
Large claims, vague technical descriptions, unusual expenditure patterns, first-time claims |
| How to protect yourself |
Keep detailed records, ensure technical descriptions are specific and evidence-based, use a qualified adviser |
| Penalty for incorrect claims |
Tax repayment + interest + potential penalties (up to 100% of overclaimed tax) |
Common Mistakes
| Mistake |
Consequence |
| Not claiming at all |
Many qualifying companies don’t realise they’re eligible |
| Claiming for routine work |
HMRC rejects the claim |
| Poor technical narrative |
Claim rejected or enquired into |
| Missing the 2-year deadline |
Claim lost entirely |
| Not keeping records |
Can’t support the claim if HMRC enquires |
| Over-claiming subcontractor costs |
Must apply the 65% restriction for unconnected parties |
| Forgetting the additional information form |
Claim is invalid without it |
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