Matthew Jones is the founder and Managing Director of LimestoneGrey, a firm of chartered tax advisers and chartered accountants specialising in R&D tax relief, based in Cardiff. He is dual-qualified: a chartered accountant with ICAEW (ACA) and a chartered tax adviser with CIOT (CTA). He is personally involved in every claim the firm submits, and every technical position published on this site is reviewed and signed off by him.
Qualifications and background
Matthew holds the ACA from the Institute of Chartered Accountants in England and Wales and the CTA from the Chartered Institute of Taxation, the two benchmark qualifications for UK accountancy and tax practice. Holding both matters in R&D work: a claim is simultaneously a tax computation, a set of accounting judgements and a technical narrative, and errors in any one of the three can sink it.
He founded LimestoneGrey in 2017 to practise R&D tax relief as a specialism rather than a sideline, and has helped companies of all sizes claim the relief they are due.
His background is in economics — a first-class BSc (Hons) and an MScEcon in Business Economics — and alongside the ACA and CTA he holds ICAEW Business and Finance Professional (BFP) status. He has specialised in R&D tax relief for over a decade.
How Matthew approaches claims
Every claim starts from the legislation, not the invoice pile. That means testing projects against the DSIT definition of qualifying R&D, interviewing the competent professionals who did the work, and drawing project boundaries that will hold up if HMRC looks closely. Where the law is unsettled, Matthew states the grey area and the position the firm takes, so clients sign off a claim they actually understand.
The same standard applies to fees and scope: the fee is agreed before work starts, and if a project does not qualify, the advice is to not claim it.
Enquiry work
HMRC checks roughly one in six R&D claims, so enquiry capability is not optional. Matthew leads the firm’s HMRC enquiry work, with enquiry support included as standard in LimestoneGrey engagements, and also takes over enquiries on claims that other advisers prepared and then walked away from.
Beyond client work
Matthew appeared on the “From Brilliant Science to Big Business” panel at the Climb26 Innovation Festival in 2026, and under his leadership LimestoneGrey was named a finalist in the One Nucleus Awards (Most Innovative Professional Services Company) and the Finance Awards Wales. The firm is regulated by ICAEW and bound by PCRT, and is registered with HMRC as a tax adviser.
Speak to Matthew
If you want a direct, qualified view on your company’s R&D position, get in touch. First conversations are with an adviser, and there is no obligation attached.
Written by Matthew Jones ACA CTA. Last reviewed July 2026.
