R&D Tax Credits for Small Businesses in the UK: A Plain-English Guide for 2026/27

Every year, thousands of UK small businesses solve hard technical problems and never claim a penny of R&D tax relief. They assume the scheme is only for laboratories and scientists. It is not. If your company builds software, improves manufacturing processes, or develops new products, you may be leaving serious money on the table.

R&D tax credits let UK companies recover part of the cost of solving genuine scientific or technological problems. As of the 2026/27 tax year, most companies claim through a single merged scheme worth 20% of qualifying spend as a taxable credit. Loss-making, R&D-intensive small businesses can instead claim Enhanced R&D Intensive Support (ERIS), worth up to 27%.

This guide explains the current rules in plain English. You will learn what counts as R&D, which scheme applies to your company, how much a claim is worth with worked examples, and how to claim step by step. Tax rules change, so confirm current figures with HMRC or gov.uk and speak to a qualified accountant before acting. This article is general information only, not financial or tax advice.

What Are R&D Tax Credits and Who Can Claim Them?

R&D tax credits are a UK government incentive that rewards companies for investing in innovation. When your company spends money trying to solve scientific or technological problems, the government effectively refunds part of that spend through the tax system. The aim is simple: make risky innovation cheaper so more businesses attempt it.

Any UK limited company that pays corporation tax can claim. There is no minimum company size and no minimum spend. You do not need a laboratory, a research department, or staff with “researcher” in their job titles. Many successful claims come from founders, engineers, and developers solving technical problems as part of their normal work.

The rules changed significantly in 2024. For accounting periods beginning on or after 1 April 2024, the old two-scheme system (the SME scheme and the separate R&D Expenditure Credit) was replaced by a single merged scheme for most companies. As of the 2026/27 tax year, the merged scheme and ERIS are the only two routes available. If you claimed under the old SME scheme in the past, the mechanics of your claim have changed, even though the underlying definition of R&D has not.

R&D relief sits naturally inside a wider tax strategy. If you are reviewing how your company manages its tax position, read our guide to tax planning strategies for small business owners.

What Counts as R&D? Qualifying and Non-Qualifying Examples

HMRC applies a two-part test. First, your project must seek an advance in science or technology. Second, it must involve resolving scientific or technological uncertainty that a competent professional could not readily work out. An advance in your own company’s knowledge is not enough. The work must push beyond what is already known or achievable in the field.

Importantly, failed projects still qualify. If your team spent six months trying to solve a problem and never cracked it, that dead end is often the strongest evidence that the uncertainty was genuine. HMRC rewards the attempt, not just the success.

Examples of work that can qualify

• Developing a new algorithm that detects payment fraud in real time at a scale existing tools cannot handle.
• Creating a manufacturing process that cuts material waste by redesigning how components are cut and joined.
• Building a prototype from a novel material where the joining method had to be invented through experimentation.
• Re-architecting a software platform to stay responsive under ten times the current load, where no off-the-shelf solution existed.
• Running systematic trials to make a food product shelf-stable without artificial preservatives.

Examples of work that does not qualify

• Building a standard website or app using established frameworks and known methods.
• Cosmetic changes to a product, such as new packaging or a colour update.
• Market research, customer surveys, and commercial feasibility studies.
• Copying a competitor’s product using publicly available techniques.
• Configuring off-the-shelf software, even if the configuration is complex.

The dividing line is uncertainty. If a competent professional in the field could have looked at the problem and known the answer, it is routine work. If the answer required experimentation, testing, and technical problem-solving, it may be R&D. When in doubt, describe the project to your accountant in terms of the problem, the unknowns, and what you tried. That conversation is often where hidden claims surface.

Merged Scheme vs ERIS: Which One Applies to Your Company?

Since April 2024, every UK company making an R&D claim falls into one of two schemes. You do not choose between them. The facts of your company decide.

The merged scheme applies to the vast majority of companies, including most SMEs. It provides an above-the-line credit worth 20% of qualifying R&D expenditure. The credit is taxable, so the net benefit depends on your corporation tax position: roughly 15% of qualifying spend for a profitable company paying the 25% main rate, and around 16.2% for a loss-making company receiving the credit as a cash payment. Our parallel guide to corporation tax rates for 2026/27 explains the rates that drive this calculation.

Enhanced R&D Intensive Support (ERIS) applies only to loss-making SMEs where qualifying R&D expenditure is at least 30% of the company’s total expenditure for the period. ERIS gives an 86% enhanced deduction plus a payable tax credit worth up to 14.5% of the surrendered loss. The effective result is a cash benefit of around 27% of qualifying spend. To qualify as an SME for this purpose, the company must have fewer than 500 staff and either turnover of no more than 100 million euros or a balance sheet total of no more than 86 million euros.

A profitable software startup with modest R&D will almost always sit in the merged scheme. A pre-revenue deep-tech company burning most of its cash on research may qualify for ERIS. If your R&D intensity sits near the 30% boundary, model both outcomes with your accountant before filing, because the difference in cash is material.

How Much Can You Get? Three Worked Illustrative Examples

The examples below are simplified illustrations to show how the maths works. They are not quotes and not a calculation of your claim. Real claims involve apportionments, caps, and timing rules. Always have an accountant check your figures.

Assume a company with 40,000 pounds of qualifying R&D spend in the 2026/27 tax year.

Example A: profitable company under the merged scheme. The credit is 20% of 40,000 pounds, which is 8,000 pounds. Because the credit is taxable, corporation tax at the 25% main rate reduces the net benefit to 6,000 pounds. That is an effective benefit of 15% of the qualifying spend.

Example B: loss-making company under the merged scheme, not ERIS-eligible. The 20% credit is paid as cash after a notional tax deduction, giving a net benefit of about 16.2% of qualifying spend. On 40,000 pounds, that is roughly 6,480 pounds in cash. Payable credits are subject to a cap based on the company’s PAYE and National Insurance liabilities, set at 20,000 pounds plus three times the annual PAYE and NIC bill. Companies with very low payrolls may receive less.

Example C: loss-making, R&D-intensive SME under ERIS. The enhanced deduction and payable credit combine to an effective benefit of around 27% of qualifying spend. On 40,000 pounds, that is roughly 10,800 pounds in cash. The same PAYE-based cap applies.

One practical point: the credit arrives after you file and HMRC processes the claim, not while you are spending the money. Build the expected timing into your cash flow forecasts so a delayed payment does not cause a shortfall. Our guide to cash flow management for small business shows how to plan for lumpy inflows like this.

What Costs Can You Include in a Claim?

Only certain categories of spending count, and each has its own rules:

• Staff costs. Gross salaries, employer National Insurance, and pension contributions for employees working directly on R&D, apportioned by the share of their time spent on qualifying work. Directors’ salaries count on the same basis.
• Subcontractors. You can include 65% of payments to subcontractors for qualifying R&D work. Under the merged scheme, overseas subcontractor costs only qualify in very limited circumstances, so most offshore development spend cannot be included.
• Externally provided workers. Agency staff working under your direction can qualify, with specific apportionment rules.
• Consumables and materials. Physical materials transformed or consumed in the R&D process, such as prototype components and testing materials.
• Software, cloud, and data costs. Licences, cloud computing, and data costs directly attributable to the R&D activity qualify. Hosting for the live commercial product does not.
• Utilities and other costs. A fair share of power, water, and fuel used directly in the R&D work can be included.

You generally cannot include capital expenditure, rent and rates, dividends, patent costs, or the cost of producing goods for sale. Keep each cost tied to a specific qualifying project and a specific accounting period, because HMRC will ask how you made the connection.

How to Claim R&D Tax Credits: The Step-by-Step Process

Follow these steps in order. Getting the sequence wrong is one of the most common reasons claims fail.

Step 1: Identify your qualifying projects. List the technical problems your team worked on during the accounting period. For each one, write down the advance you were seeking, the uncertainties you faced, and why a competent professional could not have resolved them easily.

Step 2: Gather and apportion your costs. Pull payroll records, subcontractor invoices, and receipts. Apportion staff time honestly, using timesheets, project logs, or sprint records where they exist. Estimates made a year later are far weaker than records made at the time.

Step 3: Write the technical narrative. HMRC requires an Additional Information Form for every claim. It asks for the field of science or technology, the baseline, the intended advance, the uncertainties, and how you tried to overcome them. Submit it before or at the same time as your company tax return. If the return arrives first, HMRC will remove the R&D claim from it.

Step 4: Check whether you need a claim notification. If this is your first R&D claim, or your last claim was more than three years ago, you must file a claim notification form within six months of the end of the accounting period. Miss this deadline and the claim is invalid, even though the general claim window is longer.

Step 5: File through your company tax return. Your accountant includes the claim in the CT600 with the supplementary CT600L form, marking the boxes that confirm the notification and information forms were submitted. Include bank details so HMRC can pay the credit.

Step 6: Respond to any enquiry. HMRC runs compliance checks on a proportion of claims. A clear narrative and contemporaneous records usually resolve these quickly.

Step 7: Receive the credit or payment. The credit first reduces your corporation tax bill. Any excess is paid out, subject to the PAYE cap described above.

The hard deadline for the claim itself is two years from the end of the accounting period. Treat the six-month notification deadline and the information form as equally hard. Put all three dates in your calendar the moment the period ends.

Seven Mistakes That Shrink or Sink Claims

1. Missing the claim notification deadline. First-time claimants who discover the six-month rule too late lose the entire claim for that period.
2. Claiming routine work. Dressing up standard development as R&D invites an enquiry and damages credibility for future claims.
3. A vague technical narrative. “We improved the software” says nothing. Describe the specific uncertainty and what you tried.
4. No time records. Apportioning a developer’s year to R&D from memory is guesswork. Lightweight timesheets or sprint logs made at the time are far stronger.
5. Forgetting the PAYE cap. Director-heavy companies with minimal payroll can be surprised by how the cap limits the cash credit.
6. Including overseas subcontractors. Under the merged scheme, most offshore development costs do not qualify.
7. Claiming after the window closes. Two years sounds generous until year-end accounts, audits, and filing eat most of it.

Should You Hire an R&D Tax Specialist?

You can prepare a claim with a good accountant, and many small companies do. Consider a specialist in these situations: your projects sit on the boundary of what qualifies, your R&D intensity is near the 30% ERIS threshold, you have complex subcontracting arrangements, or HMRC has opened an enquiry into a previous claim.

A good adviser will interview your technical staff, write the narrative in HMRC’s language, and defend the cost apportionments. Ask any adviser how they are paid, what happens if HMRC challenges the claim, and whether they will put their methodology in writing. Be cautious of anyone who promises a specific refund before seeing your records or who encourages you to stretch routine work into a claim. An inflated claim that collapses under enquiry costs far more than the fee you saved.

How R&D Relief Fits With Other Funding and Tax Reliefs

R&D tax credits are one piece of an early-stage funding picture. They work well alongside other reliefs because they reward money you have already spent, while other schemes help you raise money to spend.

If you are raising equity, the Seed Enterprise Investment Scheme can make your shares far more attractive to angel investors. Our founder-focused guide to SEIS tax relief for UK startups explains how to use it for your first round. R&D-intensive startups often combine SEIS fundraising with ERIS claims, since both target the same kind of early, research-heavy company.

R&D spending also deserves its own line in your budget, not a vague hope at year end. Our guide to how to create a business budget shows how to plan innovation spending so the claim process starts with clean records rather than a scramble.

Frequently Asked Questions

Can a one-person limited company claim R&D tax credits?

Yes. There is no minimum headcount. If you are a director of a limited company paying corporation tax and your work involved genuine technological uncertainty, your apportioned salary costs can form the basis of a claim.

Can sole traders claim R&D tax credits?

No. R&D tax relief is only available to companies liable for corporation tax. Sole traders and partnerships cannot claim, whatever the nature of their work.

Do failed projects qualify?

Yes. HMRC explicitly accepts that projects can fail. A documented failed attempt often proves the uncertainty was real. Keep records of what you tried and why it did not work.

Do I need a patent to claim?

No. Patents, laboratories, and research job titles are all irrelevant to eligibility. What matters is the nature of the work and the uncertainty involved.

Can I claim for previous years?

Yes, within limits. You can claim up to two years after the end of the accounting period. But if you are a first-time claimant, the six-month claim notification deadline may already have closed an older period, so act quickly and take advice.

How long does it take to receive the money?

It varies. Straightforward claims are often processed within weeks of filing, while claims selected for compliance checks take longer. Plan your cash flow as if payment will be slow.

What happens if HMRC opens an enquiry into my claim?

HMRC will ask questions about the projects, the uncertainties, and the cost calculations. Respond fully and promptly, with your records to back you up. Most enquiries into honest, well-documented claims are resolved without the claim being rejected.

Is the R&D credit taxable?

Under the merged scheme, yes. The 20% credit is brought into account as taxable income, which is why the net benefit is around 15% for a company paying the 25% main rate rather than the full 20%.

What is the PAYE cap on payable credits?

The cash credit cannot exceed 20,000 pounds plus three times the company’s PAYE and National Insurance liabilities for the period. There is an exemption for companies that are creating and managing their own intellectual property. Ask your accountant whether it applies to you.

Can I include work done by overseas subcontractors?

Under the merged scheme, overseas subcontractor costs only qualify in very limited circumstances, generally where the R&D conditions in the UK cannot be met for geographical, environmental, or legal reasons. Most offshore development spend will not qualify.

Can directors’ salaries be included?

Yes, apportioned to the time directors spent on qualifying R&D, on the same basis as other staff. Low director salaries combined with high dividends can limit the claim, which is another reason to keep genuine time records.

Should I claim every year?

If you do qualifying R&D every year, claim every year. Regular, consistent claims with good records build a track record that makes each subsequent claim smoother.

Conclusion

R&D tax credits are one of the most valuable reliefs available to innovative small companies, and the current system is simpler than the one it replaced. As of the 2026/27 tax year, remember three things: most companies claim through the merged scheme at a 20% taxable credit, loss-making R&D-intensive SMEs may do far better under ERIS at around 27%, and the deadlines are unforgiving, especially the six-month claim notification for first-time claimants.

Start with an honest review of your last accounting period. List the technical problems your team wrestled with, gather the cost records, and have the “does this count as R&D” conversation with your accountant before the notification window closes. Done properly, a claim turns money you have already spent into cash that funds your next round of innovation.

This article reflects the rules as of the 2026/27 tax year. Tax legislation changes, so verify current rates, thresholds, and deadlines with HMRC or gov.uk and speak to a qualified accountant before making a claim.