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R&D Tax Credit Calculator 2025/26

Estimate your UK R&D tax credit under the merged HMRC scheme (from April 2024). See RDEC credit, ERIS payable credit for intensive SMEs, qualifying cost breakdown by category, and cash flow timeline. Updated for 2025/26.

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Total qualifying spend on R&D activities
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All operating costs (used to calculate R&D intensity)
Yes
Determines whether you get a tax saving or a payable credit
SMEs may qualify for the enhanced ERIS scheme
Full-time equivalent employees
No
First claim or no claim in past 3 years requires pre-notification
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How to Use This Calculator

R&D Credit Estimate tab

The default tab. Enter your qualifying R&D expenditure and total company expenditure to see your estimated credit. Toggle whether your company is profitable or loss-making — this determines whether you receive a tax saving against your corporation tax bill or a payable credit from HMRC. Loss-making SMEs with R&D intensity of 30% or more qualify for the enhanced ERIS scheme at 27%.

What Counts? tab

Break down your R&D spend by category: staff costs, subcontractors, consumables, software, and cloud computing. The calculator shows what percentage qualifies in each category and your total qualifying expenditure. Subcontractor costs are capped at 65% for unconnected third parties, but 100% for connected parties (group companies).

Cash Flow Impact tab

See when you receive the benefit. Profitable companies get their credit as a reduction in their corporation tax bill at the CT payment deadline. Loss-making companies receive a payable credit from HMRC, typically 2–4 months after filing the CT600. Enter your financial year end to see exact deadlines.

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The Formula

The merged R&D scheme (from April 2024) uses an above-the-line expenditure credit:

Merged scheme (all companies):
Gross RDEC = Qualifying R&D Expenditure × 20%
Net benefit = Gross RDEC − Corporation Tax on RDEC

If profitable (25% CT rate):
Net benefit = Qualifying Expenditure × 20% × (1 − 25%) = 15%

If small profits (19% CT rate):
Net benefit = Qualifying Expenditure × 20% × (1 − 19%) = 16.2%

ERIS (loss-making SMEs, R&D intensity ≥ 30%):
Payable credit = Qualifying Expenditure × 27%

R&D intensity is calculated as qualifying R&D expenditure divided by total company expenditure. Companies must reach 30% to qualify for the enhanced ERIS rate.

Subcontractor costs: only 65% of payments to unconnected (third-party) subcontractors and externally provided workers qualifies. Connected parties (group companies) qualify at 100%.

Example

TechCo Ltd — Software Development, London

TechCo is a profitable SME with £500,000 total expenditure, of which £120,000 is qualifying R&D spend (24% R&D intensity). They pay corporation tax at the 25% main rate.

R&D Credit Calculation (Merged Scheme)

Qualifying R&D expenditure£120,000
Gross RDEC (20%)£24,000
Corporation tax on credit (25%)−£6,000
Net tax saving£18,000
Effective benefit rate15.0%

Cost Breakdown

Staff costs (developers, QA)£80,000 (100% qualifies)
Subcontractors (unconnected)£30,000 (65% = £19,500 qualifies)
Software licences£8,000 (100% qualifies)
Cloud computing£12,500 (100% qualifies)
Total qualifying£120,000

TechCo files the Additional Information Form (AIF) and then the CT600 with R&D claim by 31 March 2027. The £18,000 credit reduces their CT bill, saving cash at their payment deadline of 1 January 2027.

FAQ

The merged R&D scheme replaced both the old SME R&D tax relief and RDEC (Research and Development Expenditure Credit) schemes for accounting periods beginning on or after 1 April 2024. All companies now claim under a single scheme with a 20% above-the-line credit rate. The credit is taxable, so the net benefit is 15% for companies paying the 25% main CT rate, or 16.2% for those on the 19% small profits rate. Source: HMRC.
ERIS (Enhanced R&D Intensive Support) is a more generous scheme for loss-making SMEs that are R&D-intensive. To qualify, your qualifying R&D expenditure must be at least 30% of your total company expenditure (the threshold was lowered from 40% to 30% from April 2024). Qualifying companies receive a 27% payable tax credit from HMRC instead of the standard merged scheme rate. This is designed to support startups and early-stage companies investing heavily in R&D.
Qualifying costs include: staff costs (salaries, employer NI, pension contributions) for employees directly engaged in R&D; subcontracted R&D (65% for unconnected parties, 100% for connected); externally provided workers (65%); consumables used or transformed in R&D; software licences used directly in R&D; and cloud computing and data costs attributable to R&D (qualifying from April 2024). Costs that do NOT qualify include: capital expenditure, production/manufacturing costs, market research, rent, general administration, travel, and patent filing costs.
Since August 2023, all R&D tax credit claims must be supported by an Additional Information Form (AIF) submitted to HMRC before the CT600. The AIF requires details of your R&D projects, the scientific or technological uncertainties being resolved, and a breakdown of qualifying costs. Claims submitted without a valid AIF will be rejected. The form is submitted online through HMRC's digital service.
Yes, if you are claiming R&D tax credits for the first time or have not claimed in any of the previous 3 accounting periods, you must notify HMRC within 6 months of the end of the accounting period you are claiming for. This pre-notification is done online. If you miss the deadline, you cannot claim for that period. Companies with an ongoing claim history (claimed in at least one of the previous 3 periods) do not need to pre-notify.

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