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.

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