R&D Tax Credit Calculator

From 1 April 2024, the UK operates a merged R&D tax relief scheme replacing the previous separate SME and RDEC schemes. Under the merged scheme, qualifying companies receive a taxable above-the-line credit of 20% on eligible R&D expenditure. This credit is calculated on the total qualifying costs—staff costs, software, consumables, subcontracted R&D (at 65% of cost for connected parties), and externally provided workers (at 65%)—minus any grant or subsidised income related to the R&D.

R&D-intensive SMEs—companies where qualifying R&D expenditure represents 30% or more of total expenditure—receive an enhanced rate of 27% under the Enhanced R&D Intensive Support (ERIS) scheme. Loss-making R&D-intensive companies can surrender losses for a payable tax credit at a higher rate, providing vital cash flow for pre-revenue startups. To qualify as R&D, the project must seek an advance in science or technology by resolving scientific or technological uncertainty that a competent professional could not readily deduce.

Claims are made through the Corporation Tax return (CT600) and must include a detailed technical narrative explaining the R&D activities, the uncertainties faced, and how they were addressed. From April 2023, all claims must also be supported by a pre-notification to HMRC (if the company has not claimed in the previous three years) and include a named senior officer of the company endorsing the claim. HMRC actively investigates claims, so maintaining contemporaneous project records, timesheets, and technical documentation is critical.

What are R&D tax credits? UK government incentive for companies undertaking research and development. Two schemes: SME R&D Relief (turnover under €100M, fewer than 500 employees); RDEC (Research and Development Expenditure Credit — larger companies and certain SMEs). Significant 2024 changes: merged scheme operational from April 2024 for new claims. R&D claim reduces Corporation Tax bill OR provides cash credit for loss-makers.

Merged R&D scheme rates (April 2024+). 20% above-the-line credit on qualifying R&D expenditure. Effective net benefit: 14-16.2% of qualifying expenditure (depends on corporation tax position). Sample: £100,000 R&D spend = £20,000 credit → reduces CT bill by £20k OR cash credit ~£15k for loss-makers. Loss-makers: enhanced rate 27% (was 33% pre-April 2023) for 'R&D intensive' businesses (40%+ of total expenditure on R&D).

What qualifies as R&D for UK tax purposes. HMRC definition: 'Project that seeks to achieve advance in science or technology through resolution of scientific or technological uncertainty.' Common qualifying activities: developing new software algorithms, materials, processes, products. Improving efficiency where solution unclear. Trial and error indicates uncertainty. Doesn't qualify: routine product development, market research, aesthetic design only, social science research. Most software development excluded unless solving genuine technical challenge — HMRC scrutinises closely since 2023.

Qualifying expenditure. Staffing costs: salaries, employer NI, pension contributions for staff DIRECTLY engaged in R&D. Subcontractors: 65% of payments to non-connected subcontractors (UK and overseas restrictions from 2024). Externally Provided Workers (EPW): 65% of agency staff costs. Software and cloud computing costs (added April 2023). Consumable items (heat, light, power for R&D area). Excluded: capital expenditure (use Capital Allowances), production overheads, marketing.

Claiming R&D — process and pitfalls. Submit Additional Information Form via gov.uk BEFORE Corporation Tax return (mandatory since August 2023). Detailed technical narrative required: what was R&D, what uncertainty existed, what advance achieved. Cost breakdown by category. HMRC compliance checks doubled since 2023 — many speculative claims rejected. Use specialist R&D adviser: typical fee 15-25% of claim value (success-based) or fixed fee £2,000-£8,000. Bad advisers caused 50%+ rejection rates in 2023-2024. Choose: chartered tax adviser, member of CIOT/CIMA, or HMRC R&D-experienced accountant.