R&D Tax Credits
for SEIS founders

R&D tax credits and SEIS or EIS sit alongside each other on the SEIS or EIS-backed startup's relief stack. SEIS and EIS bring investor capital onto the balance sheet at favourable investor economics; R&D tax credits bring HMRC cash back into the company on the underlying R&D spend. For most early-stage tech and deeptech companies, the R&D credit is the largest single recurring source of non-equity cash inflow.

Under the merged R&D scheme that took effect for accounting periods beginning on or after 1 April 2024, the headline rate is 20 percent of qualifying R&D expenditure as an above-the-line credit. R&D-intensive SMEs (where qualifying R&D is at least 30 percent of total expenditure) qualify for an enhanced 27 percent rate. Most SEIS or EIS-funded technical startups are R&D-intensive in their first two or three years and so are claiming at the higher rate.

Specialist R&D claim preparation in our network combines a defensible technical narrative, a reconciled cost schedule, and explicit handling of Advance Notification (the 6-month notification deadline that applies to first-time claimants from accounting periods beginning on or after 1 April 2023). The result is a claim that resolves quickly, survives the now-frequent HMRC enquiries, and turns into actual cash inside the published service-level window.

The merged R&D scheme, in force for accounting periods beginning on or after 1 April 2024, replaced the previous separate SME and RDEC schemes with a single above-the-line credit at 20 percent of qualifying R&D expenditure. R&D-intensive SMEs (with qualifying R&D at 30 percent or more of total expenditure, reduced from the original 40 percent threshold) get an enhanced 27 percent rate via the SME-Intensive route. Most SEIS or EIS-backed tech startups in their first two or three years are R&D-intensive and claim at 27 percent. The merged scheme also brought cloud and data costs into the qualifying-cost definition for the first time, which materially increased claim values for SaaS and AI companies.

Advance Notification, in force from 1 April 2023, requires first-time claimants (companies that have not claimed R&D credits in the three previous accounting periods) to notify HMRC of an intention to claim within six months of the end of the accounting period for which the claim will be made. Missing the notification deadline means the claim cannot be filed at all for that period. The notification itself is administratively trivial (a short online form) but the deadline is unforgiving: a SEIS or EIS-backed startup with a 31 March year-end and no prior R&D claims has until 30 September of the same year to file the notification, otherwise the £200,000 of R&D credit on that period's expenditure is permanently lost.

Qualifying costs under the merged scheme are: staff costs (gross pay, employer's NI, employer's pension contributions, and a proportion of bonus) for staff working directly on the R&D project, externally provided workers (subcontracted developers and similar, with a 65 percent cap), software directly used in the R&D, cloud computing and data costs (newly added by the merged scheme), consumables, and a proportion of utilities. What does not qualify: marketing, sales, finance, general management, routine quality assurance and testing, and any indirect cost not directly attributable to the R&D project. Apportionment of staff time between R&D and non-R&D activity is the single biggest area HMRC scrutinises, and the standard approach is a documented timesheet methodology supported by sample evidence.

The technical narrative is the document HMRC reads first when reviewing a claim. It has to identify the specific scientific or technological uncertainty the project was attempting to resolve, demonstrate that the uncertainty was not readily deducible by a competent professional in the field, describe the systematic investigation undertaken to resolve it, and explain how the work sought to advance the field. Vague descriptions of 'platform development' or 'technology innovation' are now systematically enquired into by HMRC's compliance teams, and a specialist narrative grounded in the actual project (with reference to the technical lead, the project plan, and the documented uncertainties) is the difference between a claim that processes cleanly and a claim that triggers a six-month enquiry cycle.

HMRC compliance activity on R&D claims has risen substantially since 2022, with around one in five claims now subject to enquiry. The driver is the historical level of fraud and error in the SME scheme, which HMRC and the Treasury have taken seriously. Claims at higher risk are those without contemporaneous technical narratives, those with rough or rounded cost figures, those filed by generalist accountants without specific R&D experience, and those that show a high refund-to-revenue ratio. A well-prepared claim with a clear technical narrative, reconciled cost schedule, and named technical lead is far less likely to be enquired into and far more likely to resolve quickly when it is. The published HMRC service level for unenquired claims is 28 days for processing; an enquired claim typically takes three to six months to resolve.

Companies with notified state aid grants (Innovate UK Smart Grants, Innovate UK Knowledge Transfer Partnership, Wellcome Trust, MRC research grants) face a specific interaction with the R&D scheme. Costs covered by notified state aid cannot also be claimed for R&D credit under the SME route (which would be double-dipping into state aid). Under the merged scheme, the position is that grant-funded costs can usually be claimed at the lower 20 percent above-the-line rate rather than the 27 percent SME-intensive rate, but the analysis depends on the specific grant terms. A specialist accountant maps the grant-funded costs against the R&D claim and structures both to maximise the combined relief.

Subcontracted R&D and externally provided workers (EPWs) have been a recurring source of HMRC enquiry. The merged scheme made the rules cleaner: most subcontracted R&D where the customer is a UK company can be claimed by the customer at the merged-scheme rate, with the subcontractor not double-claiming. The 65 percent cap on EPW costs continues to apply (only 65 percent of the cost of an EPW counts as qualifying expenditure). Where the subcontractor is overseas, additional rules limit the claim. Specialist accountants in software development know the correct treatment of common subcontract arrangements (overseas dev shops, contractor agencies, freelance platforms).

Companies that have grown past the SME thresholds (250 employees, EUR 50 million turnover, EUR 43 million balance sheet) move from the SME-intensive route to the standard merged-scheme rate. The transition can affect the relief economics materially because the 27 percent SME-intensive rate drops to the 20 percent merged-scheme rate. Most SEIS or EIS-backed startups are nowhere near these thresholds, but knowledge-intensive companies that have raised large EIS rounds and grown rapidly can hit them. The accountant flags the transition in advance so the company has visibility into the rate change.

Pre-claim companies with significant contemporaneous R&D activity but no prior R&D claims face the Advance Notification deadline as a hard constraint. The notification can be filed before the technical narrative or the cost schedule is fully built, so the operational answer is to submit the notification on the safe side as soon as a claim becomes likely. Specialist accountants track the notification deadline against the company's accounting period as the first item on the engagement, before any other claim work begins.