R&D Tax Credit Specialists in London
Written and reviewed by the R&D Tax Accountants editorial team. Last reviewed 8 August 2026.
London has more R&D claimants than anywhere else in the UK and a business base concentrated in technology, financial and professional services, creative and media, and property. That mix produces a particular pattern of claims and a particular pattern of problems with them.
The relief is national and administered by HMRC, so nothing about the rules changes because a company is registered in the City rather than in Leeds. What changes is the shape of the typical London claim, and two features of it come up again and again.
R&D Claims in London Fintech and Software
The technology cluster around Shoreditch and Old Street, and the financial services base in the City and Canary Wharf, generate a large volume of software claims. Software is claimable, and the categories cover data licences and cloud computing as well as staff time, so the costing is usually straightforward.
The narrative is not. Financial services software is commercially novel far more often than it is technologically uncertain, and a claim that describes a product no competitor offers is describing commercial novelty. HMRC is looking for the uncertainty a competent professional could not readily resolve, which is the distinction set out on the R&D tax credits page. A payments platform that is new to market is not automatically R&D. A payments platform where the team could not establish from published knowledge whether a given consistency guarantee was achievable at a given throughput might be.
The PAYE Cap and London's Contractor Model
This is the London-specific issue. A great many companies here run small payrolls and buy their engineering through agencies or contract teams, and the payable credit is capped at £20,000 plus 300% of the company's relevant PAYE and National Insurance contributions liabilities for the period unless the company is exempt.
A founder-led company paying itself modestly, with the build delivered by an outsourced team, can generate a large qualifying figure against a very small PAYE base and find most of the expected cash unavailable. Payments for externally provided workers are also restricted to 65% where the provider is unconnected, so the same arrangement reduces the claim twice. The PAYE cap page sets out the arithmetic.
For a loss-making company relying on the credit as runway, that is the number to model before the headline rate. It is worth doing at the start of the accounting period rather than after the year end, because the payroll position is the input that can still be changed.
Where London Claims Get Questioned
Beyond the narrative and the cap, the recurring issues are group structures and grant funding. London holds a high proportion of venture-backed companies with holding structures, connected service companies and overseas parents, and each of those affects the size test, the connected party restrictions and the R&D intensity ratio.
Grant funding on the same project is the other one, and companies coming through the accelerator route frequently have it. It changes which scheme applies to which expenditure, and it needs establishing before the computation rather than after. Support bodies including the London Chamber of Commerce and Industry and the Federation of Small Businesses London are useful on the funding side, and we work with companies across Greater London and out into Croydon, Kingston, Watford, Romford and Bromley.