R&D Tax Credits (UK)

Also called: UK R&D relief, RDEC, SME R&D scheme

TL;DR

Two HMRC schemes (SME and RDEC) refunding a percentage of qualifying R&D spend in cash or as a CT credit, often £30 to 80k for early-stage UK startups.

UK R&D tax relief comes in two flavours: the SME scheme (for under-500-employee, sub-€100m turnover companies) and RDEC (for larger companies and grant-funded R&D). Post the April 2024 reforms, the SME scheme refunds roughly 27% of qualifying R&D spend for loss-making 'R&D-intensive' companies (40%+ of total spend on R&D) and ~18.6% for everyone else; RDEC pays a 20% above-the-line credit (effectively ~16.2% net).

Qualifying spend includes engineering staff, externally provided workers, software licences used in R&D, and consumables. Founders typically use a specialist R&D advisor (5 to 25% contingent fee) to file the claim alongside the corporation-tax return. The cash usually lands 4 to 8 weeks after submission and is a meaningful runway boost for early-stage tech companies.

Formula

SME Cash Credit ≈ Qualifying R&D Spend × 27% (R&D-intensive) or × 18.6% (standard)

Qualifying R&D Spend , Eligible staff, EPW, software, and consumables costs incurred during the financial year
27% , Effective cash credit rate for R&D-intensive loss-making SMEs from 1 April 2024
18.6% , Effective cash credit rate for standard loss-making SMEs from 1 April 2024

RDEC (large companies, grant-funded R&D) pays a 20% above-the-line credit, ~16.2% net of corporation tax.

Worked example

A UK pre-seed AI startup spends £180k on engineering salaries qualifying as R&D in its first year. As an R&D-intensive SME it claims a £48,600 cash credit (180k × 27%), payable as a refund 6 weeks after the CT600 is filed, almost 3 months of additional runway.

Common pitfalls

•Claiming for 'innovation' that doesn't meet HMRC's 'advance in science or technology' bar.
•Including non-qualifying staff costs (sales, marketing, finance) and triggering an HMRC enquiry.
•Leaning on an over-aggressive boutique advisor whose claims later get challenged and clawed back.

When this shows up in a pitch deck

Pitch decks for UK seed rounds often show R&D credits as a non-dilutive funding source on the use-of-funds slide.

Related terms

SEIS

UK tax-advantaged scheme giving angels up to 50% income-tax relief on up to £200k/yr invested into very early-stage UK companies.

EIS

UK scheme offering investors 30% income-tax relief on up to £1m/yr (£2m if knowledge-intensive) in qualifying UK growth-stage companies.

Runway

The number of months the current cash balance will last at the current net burn rate before the company runs out of money.

Burn Rate

The rate at which a company spends cash, typically reported monthly. Reported as either gross burn or net burn.

CIR (Crédit d'Impôt Recherche)

France's research tax credit: 30% refundable credit on the first €100M of qualifying R&D spend per year, paid as cash to loss-making startups.

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