Working out the value of your R&D tax relief doesn’t have to rely on a tool or template. Whether you’re exploring estimates manually or sense-checking results from an online R&D tax credit calculator, the steps are the same.
In this article
We break down the steps involved to help you calculate your R&D claim accurately, explaining how relief is applied and how it affects your tax position so you can build a clear view of your potential business benefit.
What rate of relief can you expect?
Your rate of relief depends on whether:
- you are a SME or a large company
- your company is profit- or loss-making
Under the merged scheme (now the default for most companies), relief is calculated as a taxable credit based on your qualifying expenditure.
For most companies under the merged scheme (from April 2024):
- Credit rate: 20%
- After corporation tax, the net benefit is typically around 15% of qualifying costs
For R&D-intensive SMEs (post-April 2023 rules still relevant for certain periods):
- Enhanced deduction rate: 86%
Step 1: Identify your qualifying projects
To claim R&D tax credits, your work must be part of a qualifying R&D project that seeks to achieve an advance in science or technology by resolving identified uncertainties. Discoveries made during routine commercial activity do not qualify unless they result from a structured project with a clear plan to address those uncertainties.
Projects can still qualify if they are ongoing or unsuccessful, and businesses may identify qualifying R&D after completion, provided they can demonstrate that the project and its objectives existed when the costs were incurred.
It is essential to separate commercial project work from qualifying R&D activities. Only tasks directly aimed at resolving scientific or technological uncertainty, along with eligible supporting activities defined in DSIT guidelines, can be included in a claim. Clearly defining project boundaries helps ensure only qualifying activities are captured.
Step 2: Check if your R&D costs qualify
Before you begin any calculation, you need to total all R&D costs from the relevant accounting period. Only specific categories can be included as R&D expenditure.
Direct staff costs
Costs for employees actively involved in the research and development work, including:
- Gross salary
- Employer NIC
- Employer pension contributions
Only the proportion spent on qualifying activities can be included.
Contractors
You may claim part of the cost of externally provided workers or subcontractors involved in eligible activity. The percentage you can include varies depending on whether your claim falls under the merged or legacy schemes. For contractors who are not connected to your company, you can claim 65% of the contractor payment.
Outsourced R&D
Work contracted to third parties to deliver part of the R&D project. Rules differ for SMEs and large companies, and rule that you cannot claim contracted costs where the R&D activity takes place abroad still apply for periods post-April 2024 with some exceptions.
Consumables and materials
Items consumed or transformed in the R&D process such as chemicals, prototypes, materials, utilities. These must be directly attributable to the eligible work.
Software
Software licences and cloud computing costs used for R&D can be included. Under the revised rules (April 2023 onwards), certain data and cloud hosting costs also qualify.
Step 3: Apply the correct scheme rules
How you apply relief depends on your company type and the rules in place for the relevant accounting period.
Loss-making SMEs
Loss-making SMEs follow the same initial steps but also have the option to surrender losses for a 14.5% payable tax credit.
Alternatively, losses can be carried forward or back and offset against taxable profits depending on what delivers the best outcome for the company.
Example
Qualifying expenditure: £200,000
Pre-R&D trading loss: £150,000
| Enhanced expenditure | £172,000 |
| Revised loss | £150,000 + £172,000 = £322,000 |
| Payable tax credit at 14.5% | £46,690 cash credit |
Merged scheme RDEC (most companies from April 2024)
Most companies now fall under the merged scheme. Here:
- Multiply qualifying expenditure by the 20% credit rate.
- Since the credit is taxable, apply corporation tax.
- The remaining balance is your net R&D benefit.
This credit appears “above the line” in your profit and loss account.
Example
Qualifying expenditure: £500,000
| Credit at 20% | £100,000 |
| Corporation tax on credit at 25% | £25,000 |
| Net benefit | £75,000 |
How the RDEC is realised into cash
The RDEC benefit is applied in a set order to determine how the credit is used or paid to a company:
Offset against Corporation Tax
The gross credit is first used to reduce the company’s Corporation Tax liability for the relevant accounting period.
Limit to net benefit
Any remaining credit is compared to the net expenditure credit (after Corporation Tax). Amounts above this threshold may be carried forward or group relieved.
PAYE and NIC Cap
The credit may then be restricted based on the company’s PAYE and National Insurance contributions relating to R&D staff. Any excess is carried forward.
Offset against other Corporation Tax liabilities
Remaining credit is applied to settle any outstanding Corporation Tax from other accounting periods.
Group relief option
The company may choose to surrender any remaining credit to other group companies.
Offset against other HMRC liabilities
HMRC will offset any balance against other tax liabilities, such as VAT or PAYE.
Cash payment
Any remaining credit can be paid directly to the company, provided it is considered a going concern.
Choosing Ayming as your partner
If you need support identifying eligible activity or calculating your benefit accurately, our specialists can help you navigate the process with confidence.
And if you’ve already used an R&D tax credit calculator and want tailored advice on what the numbers really mean, we can help with that too.
How Do R&D Tax Claims Actually Work?