You do not have to be inventing the next smartphone to claim R&D tax relief. Plenty of small UK businesses — from software developers to food manufacturers to engineering firms — qualify without realising it. But the rules have tightened considerably, and getting a claim wrong can be costly.

This article is general information, not financial or legal advice. Rules and figures change, so always check the latest guidance on GOV.UK or speak to a qualified accountant.

What Is R&D Tax Relief?

Research and Development (R&D) tax relief is a government incentive that reduces a company's corporation tax bill — or, in some cases, results in a cash payment from HMRC — in exchange for money spent on qualifying research and development activities. It exists to encourage UK companies to innovate.

The scheme has undergone significant reform. HMRC merged the previous SME scheme and the large-company RDEC scheme into a single "merged scheme" for most claimants. There is also a separate, more generous rate for R&D-intensive loss-making companies. The current rules, rates, and thresholds are on GOV.UK — always check there for the figures that apply to your accounting period.

What Counts as R&D? (Plain English)

This is where many businesses either over-claim or under-claim. HMRC's definition of R&D is based on the concept of "resolving scientific or technological uncertainty." In plain English, that means you are trying to work out how to do something that is not obvious to a competent professional in your field.

Some examples of what might qualify:

  • Developing new software functionality that requires solving a technical problem with no off-the-shelf solution
  • Creating a new product with properties that existing products do not have
  • Adapting a manufacturing process in a way that is genuinely novel
  • Testing and iterating on formulations, algorithms, or systems where the outcome is uncertain

What does not qualify includes routine development work, making cosmetic changes to existing products, applying known techniques to a new market, or copying what competitors already do. The uncertainty has to be genuine and technical in nature.

What Costs Can You Claim?

Once you have identified qualifying R&D activities, you can include certain costs in your claim:

  • Staff costs: Salaries, employer National Insurance, and pension contributions for employees directly involved in R&D work — including a proportion of time for those who split their work between R&D and other tasks.
  • Subcontractors and freelancers: There are rules here about which costs qualify and at what rate — check the current guidance carefully.
  • Consumables: Materials and utilities used up directly in the R&D process.
  • Software: Software used directly in the R&D activity.
  • Cloud computing: Qualifying costs for cloud platforms used in R&D.

You cannot claim for the cost of capital assets (equipment) through R&D relief — though you may be able to claim capital allowances on these separately, as explained in our guide to full expensing and capital allowances.

Good R&D claims are built on good records. If you cannot show what your staff actually did, when they did it, and what technical problem they were trying to solve, your claim is vulnerable — no matter how good it looks on paper.

How to Claim

R&D relief is claimed through your company's corporation tax return (CT600). You will also need to submit an Additional Information Form to HMRC before or at the same time as your return — this form asks for details about the R&D activities and costs. HMRC introduced this requirement to tackle the high volume of incorrect and fraudulent claims.

The process in brief:

  1. Identify which activities in your business genuinely qualify as R&D under HMRC's definition.
  2. Calculate the qualifying costs for those activities.
  3. Complete the Additional Information Form on HMRC's portal.
  4. Include the claim in your CT600.

You can amend a return to add an R&D claim up to two years after the end of the accounting period. But do not leave it too long — gathering evidence gets harder the further back you go.

Keeping Evidence

HMRC compliance checks on R&D claims have increased substantially. Keep the following:

  • Technical records explaining the uncertainty you were trying to resolve
  • Timesheets or logs showing how much time staff spent on qualifying activities
  • Invoices and contracts for subcontractors and materials
  • Meeting notes, development logs, and version histories where relevant

Think of it this way: if HMRC opened an enquiry tomorrow, could you explain in plain terms what the technical challenge was and what work your team did to solve it? If yes, your claim is defensible. If not, it needs more work.

Avoiding Risky Advisers

The R&D claims market attracted a wave of unscrupulous advisory firms that inflated claims, took large success fees, and left businesses exposed to HMRC enquiries and penalties. Be cautious of any adviser who:

  • Guarantees a large refund before reviewing your activities
  • Charges a very high percentage fee and has no other income model
  • Does not ask detailed questions about the technical nature of your work
  • Pressures you to sign quickly

A legitimate R&D adviser will spend time understanding your business, ask technical questions, and tell you honestly if your activities are unlikely to qualify. If a claim goes wrong, it is your company — not the adviser — that faces HMRC's penalties.

Is It Worth It?

For businesses genuinely carrying out qualifying work, yes — R&D relief can return meaningful sums. But a poorly prepared claim creates risk, takes time to defend, and can damage your relationship with HMRC. Do it properly, keep your records, and get advice from someone with a track record of clean, successful claims.