Research and development (R&D) tax credits are a non-refundable cash injection that companies can claim when filing their tax returns if they conduct R&D activities. Your company does not need to be profitable to benefit, both loss-making and profit-making companies can benefit from the R&D tax credits regime. It can be worth Tens of Thousands of pounds worth of relief (and more).
The definition of R&D is very broad, it includes much more than the conventional perception of R&D (staff in white labs coats researching medical treatment is the usual perception). It can include many different areas in industry where it may not seem on initial glance it is R&D but for the R&D tax credits regime it can be, and as a result, large refunds are issued by HMRC to companies who make a claim.